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1. Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode

Author

Algaba, J. C., Balokovic, M., Chandra, S., Cheong, W. Y., Cui, Y. Z., D'Ammando, F., Falcone, A. D., Ford, N. M., Giroletti, M., Goddi, C., Gurwell, M. A., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Kerby, S., Kim, J. Y., Kino, M., Kravchenko, E. V., Lee, S. S., Lu, R. S., Markoff, S., Michail, J., Neilsen, J., Nowak, M. A., Principe, G., Ramakrishnan, V., Ripperda, B., Sasada, M., Savchenko, S. S., Sheridan, C., group, The Event Horizon Telescope - Multi-wavelength science working, Collaboration, The Event Horizon Telescope, Collaboration, The Fermi Large Area Telescope, Collaboration, H. E. S. S., Collaboration, MAGIC, Collaboration, VERITAS, and Collaboration, EAVN

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL) facilities (from radio to gamma-ray energies) took part in the second M87 EHT campaign. The goal of this extensive MWL campaign was to better understand the physics of the accreting black hole M87*, the relationship between the inflow and inner jets, and the high-energy particle acceleration. Understanding the complex astrophysics is also a necessary first step towards performing further tests of general relativity. The MWL campaign took place in April 2018, overlapping with the EHT M87* observations. We present a new, contemporaneous spectral energy distribution (SED) ranging from radio to very high energy (VHE) gamma-rays, as well as details of the individual observations and light curves. We also conduct phenomenological modelling to investigate the basic source properties. We present the first VHE gamma-ray flare from M87 detected since 2010. The flux above 350 GeV has more than doubled within a period of about 36 hours. We find that the X-ray flux is enhanced by about a factor of two compared to 2017, while the radio and millimetre core fluxes are consistent between 2017 and 2018. We detect evidence for a monotonically increasing jet position angle that corresponds to variations in the bright spot of the EHT image. Our results show the value of continued MWL monitoring together with precision imaging for addressing the origins of high-energy particle acceleration. While we cannot currently pinpoint the precise location where such acceleration takes place, the new VHE gamma-ray flare already presents a challenge to simple one-zone leptonic emission model approaches, and emphasises the need for combined image and spectral modelling., Comment: 46 pages, 23 figures, accepted by Astronomy & Astrophysics on August. 29, 2024

Published
2024

2. Ordered magnetic fields around the 3C 84 central black hole

Author

Paraschos, G. F., Kim, J. -Y., Wielgus, M., Röder, J., Krichbaum, T. P., Ros, E., Agudo, I., Myserlis, I., Moscibrodzka, M., Traianou, E., Zensus, J. A., Blackburn, L., Chan, C. -K., Issaoun, S., Janssen, M., Johnson, M. D., Fish, V. L., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Baloković, M., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chang, D. O., Chatterjee, K., Chatterjee, S., Chen, M. T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Dahale, R., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fomalont, E., Ford, H. A., Foschi, M., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gómez-Ruiz, A. I., Gómez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., James, D. J., Jannuzi, B. T., Jeter, B., Jaing, W., Jiménez-Rosales, A., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, J. A., Kramer, M., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lowitz, A. E., Lu, R. -S., MacDonald, N. R., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Mulaudzi, W., Müller, C., Müller, H., Mus, A., Musoke, G., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. Navarro, Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Özel, F., Palumbo, D. C. M., Park, J., Parsons, H., Patel, N., Pen, U. -L., Piétu, V., Plambeck, R., PopStefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Romero-Cañizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K., Shao, L., Shen, Z., Small, D., Sohn, B. W., SooHoo, J., Salas, L. D. Sosapanta, Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Toscano, T., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Washington, J. E., Weintroub, J., Wharton, R., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yadlapalli, N., Yamaguchi, P., Yfantis, A., Yoon, D., Young, A., Young, K., Younsi, Z., Yu, W., Yuan, F., Yuan, Y. -F., Zhang, S., Zhao, G. Y., and Zhao, S. -S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

3C84 is a nearby radio source with a complex total intensity structure, showing linear polarisation and spectral patterns. A detailed investigation of the central engine region necessitates the use of VLBI above the hitherto available maximum frequency of 86GHz. Using ultrahigh resolution VLBI observations at the highest available frequency of 228GHz, we aim to directly detect compact structures and understand the physical conditions in the compact region of 3C84. We used EHT 228GHz observations and, given the limited (u,v)-coverage, applied geometric model fitting to the data. We also employed quasi-simultaneously observed, multi-frequency VLBI data for the source in order to carry out a comprehensive analysis of the core structure. We report the detection of a highly ordered, strong magnetic field around the central, SMBH of 3C84. The brightness temperature analysis suggests that the system is in equipartition. We determined a turnover frequency of $\nu_m=(113\pm4)$GHz, a corresponding synchrotron self-absorbed magnetic field of $B_{SSA}=(2.9\pm1.6)$G, and an equipartition magnetic field of $B_{eq}=(5.2\pm0.6)$G. Three components are resolved with the highest fractional polarisation detected for this object ($m_\textrm{net}=(17.0\pm3.9)$%). The positions of the components are compatible with those seen in low-frequency VLBI observations since 2017-2018. We report a steeply negative slope of the spectrum at 228GHz. We used these findings to test models of jet formation, propagation, and Faraday rotation in 3C84. The findings of our investigation into different flow geometries and black hole spins support an advection-dominated accretion flow in a magnetically arrested state around a rapidly rotating supermassive black hole as a model of the jet-launching system in the core of 3C84. However, systematic uncertainties due to the limited (u,v)-coverage, however, cannot be ignored., Comment: 15 pages, 6 figures, published in A&A

Published
2024
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3. Three-dimensional dynamics of strongly twisted magnetar magnetospheres: Kinking flux tubes and global eruptions

Author

Mahlmann, J. F., Philippov, A. A., Mewes, V., Ripperda, B., Most, E. R., and Sironi, L.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, Physics - Plasma Physics
Abstract

The origins of the various outbursts of hard X-rays from magnetars (highly magnetized neutron stars) are still unknown. We identify instabilities in relativistic magnetospheres that can explain a range of X-ray flare luminosities. Crustal surface motions can twist the magnetar magnetosphere by shifting the frozen-in footpoints of magnetic field lines in current-carrying flux bundles. Axisymmetric (2D) magnetospheres exhibit strong eruptive dynamics, as to say, catastrophic lateral instabilities triggered by a critical footpoint displacement of $\psi_{\rm crit}\gtrsim\pi$. In contrast, our new three-dimensional (3D) twist models with finite surface extension capture important non-axisymmetric dynamics of twisted force-free flux bundles in dipolar magnetospheres. Besides the well-established global eruption resulting (as in 2D) from lateral instabilities, such 3D structures can develop helical, kink-like dynamics, and dissipate energy locally (confined eruptions). Up to $25\%$ of the induced twist energy is dissipated and available to power X-ray flares in powerful global eruptions, with most of our models showing an energy release in the range of the most common X-ray outbursts, $\lesssim 10^{43}$erg. Such events occur when significant energy builds up deeply buried in the dipole magnetosphere. Less energetic outbursts likely precede powerful flares, due to intermittent instabilities and confined eruptions of a continuously twisting flux tube. Upon reaching a critical state, global eruptions produce the necessary Poynting-flux-dominated outflows required by models prescribing the fast radio burst production in the magnetar wind -- for example, via relativistic magnetic reconnection or shocks., Comment: 21 pages, 11 figures, Accepted for publication by ApJL

Published
2023
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4. Weak Alfv\'{e}nic turbulence in relativistic plasmas. Part 1. Dynamical equations and basic dynamics of interacting resonant triads

Author

TenBarge, J. M., Ripperda, B., Chernoglazov, A., Bhattacharjee, A., Mahlmann, J. F., Most, E. R., Juno, J., Yuan, Y., and Philippov, A. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, Physics - Plasma Physics, Physics - Space Physics
Abstract

Alfv\'{e}n wave collisions are the primary building blocks of the non-relativistic turbulence that permeates the heliosphere and low-to-moderate energy astrophysical systems. However, many astrophysical systems such as gamma-ray bursts, pulsar and magnetar magnetospheres, and active galactic nuclei have relativistic flows or energy densities. To better understand these high energy systems, we derive reduced relativistic MHD equations and employ them to examine weak Alfv\'{e}nic turbulence, dominated by three-wave interactions, in reduced relativistic magnetohydrodynamics, including the force-free, infinitely magnetized limit. We compare both numerical and analytical solutions to demonstrate that many of the findings from non-relativistic weak turbulence are retained in the relativistic system. But, an important distinction in the relativistic limit is the inapplicability of a formally incompressible limit, i.e, there exists finite coupling to the compressible fast mode regardless of the strength of the magnetic field. Since fast modes can propagate across field lines, this mechanism provides a route for energy to escape strongly magnetized systems, e.g., magnetar magnetospheres. However, we find that the fast-Alfv\'{e}n coupling is diminished in the limit of oblique propagation., Comment: Accepted

Published
2021
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5. Weak Alfv\'enic turbulence in relativistic plasmas II: Current sheets and dissipation

Author

Ripperda, B., Mahlmann, J. F., Chernoglazov, A., TenBarge, J. M., Most, E. R., Juno, J., Yuan, Y., Philippov, A. A., and Bhattacharjee, A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, Physics - Plasma Physics, Physics - Space Physics
Abstract

Alfv\'{e}n waves as excited in black hole accretion disks and neutron star magnetospheres are the building blocks of turbulence in relativistic, magnetized plasmas. A large reservoir of magnetic energy is available in these systems, such that the plasma can be heated significantly even in the weak turbulence regime. We perform high-resolution three-dimensional simulations of counter-propagating Alfv\'{e}n waves, showing that an $E_{B_{\perp}}(k_{\perp}) \propto k_{\perp}^{-2}$ energy spectrum develops as a result of the weak turbulence cascade in relativistic magnetohydrodynamics and its infinitely magnetized (force-free) limit. The plasma turbulence ubiquitously generates current sheets, which act as locations where magnetic energy dissipates. We show that current sheets form as a natural result of nonlinear interactions between counter-propagating Alfv\'{e}n waves. These current sheets form due to the compression of elongated eddies, driven by the shear induced by growing higher order modes, and undergo a thinning process until they break-up into small-scale turbulent structures. We explore the formation of {current sheets} both in overlapping waves and in localized wave packet collisions. The relativistic interaction of localized Alfv\'{e}n waves induces both Alfv\'{e}n waves and fast waves and efficiently mediates the conversion and dissipation of electromagnetic energy in astrophysical systems. Plasma energization through reconnection in current sheets emerging during the interaction of Alfv\'{e}n waves can potentially explain X-ray emission in black hole accretion coronae and neutron star magnetospheres., Comment: Accepted in JPP, accompanied by Paper I: Weak Alfv\'enic turbulence in relativistic plasmas I: dynamical equations and basic dynamics of interacting resonant triads

Published
2021
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6. SYMBA: An end-to-end VLBI synthetic data generation pipeline

Author

Roelofs, F., Janssen, M., Natarajan, I., Deane, R., Davelaar, J., Olivares, H., Porth, O., Paine, S. N., Bouman, K. L., Tilanus, R. P. J., van Bemmel, I. M., Falcke, H., Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Baczko, A., Ball, D., Baloković, M., Barrett, J., Bintley, D., Blackburn, L., Boland, W., Bower, G. C., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D., Carlstrom, J. E., Chael, A., Chan, C., Chatterjee, S., Chatterjee, K., Chen, M., Chen, Y., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crew, G. B., Cui, Y., De Laurentis, M., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Fish, V. L., Fomalont, E., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Gómez, J. L., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gu, M., Gurwell, M., Hada, K., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. L., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Jeter, B., Jiang, W., Johnson, M. D., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, J., Kino, M., Koay, J. Yi, Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Krichbaum, T. P., Kuo, C., Lauer, T. R., Lee, S., Li, Y., Li, Z., Lindqvist, M., Lico, R., Liu, K., Liuzzo, E., Lo, W., Lobanov, A. P., Loinard, L., Lonsdale, C., Lu, R., MacDonald, N. R., Mao, J., Markoff, S., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, Y., Mizuno, I., Moran, J. M., Moriyama, K., Moscibrodzka, M., Müller, C., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Neri, R., Ni, C., Noutsos, A., Okino, H., Ortiz-León, G. N., Oyama, T., Özel, F., Palumbo, D. C. M., Patel, N., Pen, U., Pesce, D. W., Piétu, V., Plambeck, R., PopStefanija, A., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ripperda, B., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Ryan, B. R., Rygl, K. L. J., Sánchez, S., Sánchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. Peter, Schuster, K., Shao, L., Shen, Z., Small, D., Sohn, B. Won, SooHoo, J., Tazaki, F., Tiede, P., Titus, M., Toma, K., Torne, P., Trent, T., Trippe, S., Tsuda, S., van Langevelde, H. J., van Rossum, D. R., Wagner, J., Wardle, J., Ward-Thompson, D., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y., Zensus, J. A., Zhao, G., Zhao, S., and Zhu, Z.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Realistic synthetic observations of theoretical source models are essential for our understanding of real observational data. In using synthetic data, one can verify the extent to which source parameters can be recovered and evaluate how various data corruption effects can be calibrated. These studies are important when proposing observations of new sources, in the characterization of the capabilities of new or upgraded instruments, and when verifying model-based theoretical predictions in a comparison with observational data. We present the SYnthetic Measurement creator for long Baseline Arrays (SYMBA), a novel synthetic data generation pipeline for Very Long Baseline Interferometry (VLBI) observations. SYMBA takes into account several realistic atmospheric, instrumental, and calibration effects. We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a mm VLBI array, which has recently captured the first image of a black hole shadow. After testing SYMBA with simple source and corruption models, we study the importance of including all corruption and calibration effects. Based on two example general relativistic magnetohydrodynamics (GRMHD) model images of M87, we performed case studies to assess the attainable image quality with the current and future EHT array for different weather conditions. The results show that the effects of atmospheric and instrumental corruptions on the measured visibilities are significant. Despite these effects, we demonstrate how the overall structure of the input models can be recovered robustly after performing calibration steps. With the planned addition of new stations to the EHT array, images could be reconstructed with higher angular resolution and dynamic range. In our case study, these improvements allowed for a distinction between a thermal and a non-thermal GRMHD model based on salient features in reconstructed images., Comment: 20 pages, 15 figures, accepted for publication in A&A

Published
2020
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8. Reconnection and particle acceleration in interacting flux ropes -- II. 3D effects on test particles in magnetically dominated plasmas

Author

Ripperda, B., Porth, O., Xia, C., and Keppens, R.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We analyze particle acceleration in explosive reconnection events in magnetically dominated proton-electron plasmas. Reconnection is driven by large-scale magnetic stresses in interacting current-carrying flux tubes. Our model relies on development of current-driven instabilities on macroscopic scales. These tilt-kink instabilities develop in an initially force-free equilibrium of repelling current channels. Using MHD methods we study a 3D model of repelling and interacting flux tubes in which we simultaneously evolve test particles, guided by electromagnetic fields obtained from MHD. We identify two stages of particle acceleration; Initially particles accelerate in the current channels, after which the flux ropes start tilting and kinking and particles accelerate due to reconnection processes in the plasma. The explosive stage of reconnection produces non-thermal energy distributions with slopes that depend on plasma resistivity and the initial particle velocity. We also discuss the influence of the length of the flux ropes on particle acceleration and energy distributions. This study extends previous 2.5D results to 3D setups, providing all ingredients needed to model realistic scenarios like solar flares, black hole flares and particle acceleration in pulsar wind nebulae: formation of strong resistive electric fields, explosive reconnection and non-thermal particle distributions. By assuming initial energy equipartition between electrons and protons, applying low resistivity in accordance with solar corona conditions and limiting the flux rope length to a fraction of a solar radius we obtain realistic energy distributions for solar flares with non-thermal power law tails and maximum electron energies up to 11 MeV and maximum proton energies up to 1 GeV., Comment: Matches published version in MNRAS, including Erratum

Published
2017
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9. Resolution analysis of magnetically arrested disc simulations.

Author

Salas, L D S, Musoke, G, Chatterjee, K, Markoff, S B, Porth, O, Liska, M T P, and Ripperda, B

Subjects
POLOIDAL magnetic fields, ANGULAR momentum (Mechanics), ACCRETION disks, BLACK holes, ENERGY dissipation
Abstract

Polarization measurements by the Event Horizon Telescope from M87* and Sgr A* suggest that there is a dynamically strong, ordered magnetic field, typical of what is expected of a magnetically arrested accretion disc (MAD). In such discs, the strong poloidal magnetic field can suppress the accretion flow and cause episodic flux eruptions. Recent work shows that general relativistic magnetohydrodynamic (GRMHD) MAD simulations feature dynamics of turbulence and mixing instabilities that are becoming resolved at higher resolutions. We perform a convergence study of MAD states exceeding the status quo by an order of magnitude in resolution. We use existing 3D simulations performed with the H-AMR code, up to a resolution of 5376 × 2304 × 2304 in a logarithmic spherical-polar grid. We find consistent time-averaged disc properties across all resolutions. However, higher resolutions reveal signs of inward angular momentum transport attributed to turbulent convection, particularly evident when mixing instabilities occur at the surfaces of flux tubes during flux eruptions. Additionally, we see wave-like features in the jet sheath, which become more prominent at higher resolutions, that may induce mixing between the jet and disc. At higher resolutions, we observe the sheath to be thinner, resulting in increased temperature, reduced magnetization, and greater variability. Those differences could affect the dissipation of energy, which would eventually result in distinct observable radiative emission from high-resolution simulations. With higher resolutions, we can delve into crucial questions about horizon-scale physics and its impact on the dynamics and emission properties of larger-scale jets. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Ordered magnetic fields around the 3C 84 central black hole

Author

Paraschos, G. F., primary, Kim, J.-Y., additional, Wielgus, M., additional, Röder, J., additional, Krichbaum, T. P., additional, Ros, E., additional, Agudo, I., additional, Myserlis, I., additional, Moscibrodzka, M., additional, Traianou, E., additional, Zensus, J. A., additional, Blackburn, L., additional, Chan, C.-K., additional, Issaoun, S., additional, Janssen, M., additional, Johnson, M. D., additional, Fish, V. L., additional, Akiyama, K., additional, Alberdi, A., additional, Alef, W., additional, Algaba, J. C., additional, Anantua, R., additional, Asada, K., additional, Azulay, R., additional, Bach, U., additional, Baczko, A.-K., additional, Ball, D., additional, Baloković, M., additional, Barrett, J., additional, Bauböck, M., additional, Benson, B. A., additional, Bintley, D., additional, Blundell, R., additional, Bouman, K. L., additional, Bower, G. C., additional, Boyce, H., additional, Bremer, M., additional, Brinkerink, C. D., additional, Brissenden, R., additional, Britzen, S., additional, Broderick, A. E., additional, Broguiere, D., additional, Bronzwaer, T., additional, Bustamante, S., additional, Byun, D.-Y., additional, Carlstrom, J. E., additional, Ceccobello, C., additional, Chael, A., additional, Chang, D. O., additional, Chatterjee, K., additional, Chatterjee, S., additional, Chen, M. T., additional, Chen, Y., additional, Cheng, X., additional, Cho, I., additional, Christian, P., additional, Conroy, N. S., additional, Conway, J. E., additional, Cordes, J. M., additional, Crawford, T. M., additional, Crew, G. B., additional, Cruz-Osorio, A., additional, Cui, Y., additional, Dahale, R., additional, Davelaar, J., additional, De Laurentis, M., additional, Deane, R., additional, Dempsey, J., additional, Desvignes, G., additional, Dexter, J., additional, Dhruv, V., additional, Doeleman, S. S., additional, Dougal, S., additional, Dzib, S. A., additional, Eatough, R. P., additional, Emami, R., additional, Falcke, H., additional, Farah, J., additional, Fomalont, E., additional, Ford, H. A., additional, Foschi, M., additional, Fraga-Encinas, R., additional, Freeman, W. T., additional, Friberg, P., additional, Fromm, C. M., additional, Fuentes, A., additional, Galison, P., additional, Gammie, C. F., additional, García, R., additional, Gentaz, O., additional, Georgiev, B., additional, Goddi, C., additional, Gold, R., additional, Gómez-Ruiz, A. I., additional, Gómez, J. L., additional, Gu, M., additional, Gurwell, M., additional, Hada, K., additional, Haggard, D., additional, Haworth, K., additional, Hecht, M. H., additional, Hesper, R., additional, Heumann, D., additional, Ho, L. C., additional, Ho, P., additional, Honma, M., additional, Huang, C. L., additional, Huang, L., additional, Hughes, D. H., additional, Ikeda, S., additional, Impellizzeri, C. M. V., additional, Inoue, M., additional, James, D. J., additional, Jannuzi, B. T., additional, Jeter, B., additional, Jaing, W., additional, Jiménez-Rosales, A., additional, Jorstad, S., additional, Joshi, A. V., additional, Jung, T., additional, Karami, M., additional, Karuppusamy, R., additional, Kawashima, T., additional, Keating, G. K., additional, Kettenis, M., additional, Kim, D.-J., additional, Kim, J., additional, Kino, M., additional, Koay, J. Y., additional, Kocherlakota, P., additional, Kofuji, Y., additional, Koch, P. M., additional, Koyama, S., additional, Kramer, C., additional, Kramer, J. A., additional, Kramer, M., additional, Kuo, C.-Y., additional, La Bella, N., additional, Lauer, T. R., additional, Lee, D., additional, Lee, S.-S., additional, Leung, P. K., additional, Levis, A., additional, Li, Z., additional, Lico, R., additional, Lindahl, G., additional, Lindqvist, M., additional, Lisakov, M., additional, Liu, J., additional, Liu, K., additional, Liuzzo, E., additional, Lo, W.-P., additional, Lobanov, A. 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Published
2024
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15. Synchrotron Polarization Signatures of Surface Waves in Supermassive Black Hole Jets

Author

Davelaar, J., Ripperda, B., Sironi, L., Philippov, A.A., Olivares, H., Porth, O., Berg, B.v.d., Bronzwaer, T.J.W., Chatterjee, K., Liska, M., Davelaar, J., Ripperda, B., Sironi, L., Philippov, A.A., Olivares, H., Porth, O., Berg, B.v.d., Bronzwaer, T.J.W., Chatterjee, K., and Liska, M.

Abstract

Contains fulltext : 299922.pdf (Publisher’s version ) (Open Access)

Published
2023

20. First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near the Event Horizon

Author

Akiyama, K. Algaba, J.C. Alberdi, A. Alef, W. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Baloković, M. Barrett, J. Benson, B.A. Bintley, D. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. Garciá, R. Gelles, Z. Gentaz, O. Georgiev, B. Goddi, C. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Himwich, E. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Krichbaum, T.P. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. Macdonald, N.R. Mao, J. Marchili, N. Markoff, S. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejiás, A.M. Michalik, D. Nadolski, A. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neilsen, J. Neri, R. Ni, C. Noutsos, A. Nowak, M.A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. zel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Ramakrishnan, V. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Bemmel, I.V. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotron radiation probes the structure of magnetic fields and the plasma properties near the black hole. Here we compare the resolved polarization structure observed by the EHT, along with simultaneous unresolved observations with the Atacama Large Millimeter/submillimeter Array, to expectations from theoretical models. The low fractional linear polarization in the resolved image suggests that the polarization is scrambled on scales smaller than the EHT beam, which we attribute to Faraday rotation internal to the emission region. We estimate the average density n e ∼ 104-7 cm-3, magnetic field strength B ∼ 1-30 G, and electron temperature T e ∼ (1-12) 1010 K of the radiating plasma in a simple one-zone emission model. We show that the net azimuthal linear polarization pattern may result from organized, poloidal magnetic fields in the emission region. In a quantitative comparison with a large library of simulated polarimetric images from general relativistic magnetohydrodynamic (GRMHD) simulations, we identify a subset of physical models that can explain critical features of the polarimetric EHT observations while producing a relativistic jet of sufficient power. The consistent GRMHD models are all of magnetically arrested accretion disks, where near-horizon magnetic fields are dynamically important. We use the models to infer a mass accretion rate onto the black hole in M87 of (3-20) 10-4 M o˙ yr-1. © 2021. The Author(s). Published by the American Astronomical Society..

Published
2021

21. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author

Algaba, J.C. Anczarski, J. Asada, K. Baloković, M. Chandra, S. Cui, Y.-Z. Falcone, A.D. Giroletti, M. Goddi, C. Hada, K. Haggard, D. Jorstad, S. Kaur, A. Kawashima, T. Keating, G. Kim, J.-Y. Kino, M. Komossa, S. Kravchenko, E.V. Krichbaum, T.P. Lee, S.-S. Lu, R.-S. Lucchini, M. Markoff, S. Neilsen, J. Nowak, M.A. Park, J. Principe, G. Ramakrishnan, V. Reynolds, M.T. Sasada, M. Savchenko, S.S. Williamson, K.E. Akiyama, K. Alberdi, A. Alef, W. Anantua, R. Azulay, R. Baczko, A.-K. Ball, D. Barrett, J. Bintley, D. Benson, B.A. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jiménez-Rosales, A. Johnson, M.D. Jung, T. Karami, M. Karuppusamy, R. Kettenis, M. Kim, D.-J. Kim, J. Kim, J. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Macdonald, N.R. Mao, J. Marchili, N. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neri, R. Ni, C. Noutsos, A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. Ozel, F. Palumbo, D.C.M. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Van Bemmel, I. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. Principe, G. Giroletti, M. D'Ammando, F. Orienti, M. Abdalla, H. Adam, R. Aharonian, F. Benkhali, F.A. Angüner, E.O. Arcaro, C. Armand, C. Armstrong, T. Ashkar, H. Backes, M. Baghmanyan, V. Barbosa Martins, V. Barnacka, A. Barnard, M. Becherini, Y. Berge, D. Bernlöhr, K. Bi, B. Böttcher, M. Boisson, C. Bolmont, J. De Bony De Lavergne, M. Breuhaus, M. Brun, F. Brun, P. Bryan, M. Büchele, M. Bulik, T. Bylund, T. Caroff, S. Carosi, A. Casanova, S. Chand, T. Chen, A. Cotter, G. Curyło, M. Damascene Mbarubucyeye, J. Davids, I.D. Davies, J. Deil, C. Devin, J. Dewilt, P. Dirson, L. Djannati-Ataï, A. Dmytriiev, A. Donath, A. Doroshenko, V. Duffy, C. Dyks, J. Egberts, K. Eichhorn, F. Einecke, S. Emery, G. Ernenwein, J.-P. Feijen, K. Fegan, S. Fiasson, A. De Clairfontaine, G.F. Fontaine, G. Funk, S. Füßling, M. Gabici, S. Gallant, Y.A. Giavitto, G. Giunti, L. Glawion, D. Glicenstein, J.F. Gottschall, D. Grondin, M.-H. Hahn, J. Haupt, M. Hermann, G. Hinton, J.A. Hofmann, W. Hoischen, C. Holch, T.L. Holler, M. Hörbe, M. Horns, D. Huber, D. Jamrozy, M. Jankowsky, D. Jankowsky, F. Jardin-Blicq, A. Joshi, V. Jung-Richardt, I. Kasai, E. Kastendieck, M.A. Katarzyński, K. Katz, U. Khangulyan, D. Khélifi, B. Klepser, S. Kluźniak, W. Komin, N. Konno, R. Kosack, K. Kostunin, D. Kreter, M. Lamanna, G. Lemiere, A. Lemoine-Goumard, M. Lenain, J.-P. Levy, C. Lohse, T. Lypova, I. Mackey, J. Majumdar, J. Malyshev, D. Malyshev, D. Marandon, V. Marchegiani, P. Marcowith, A. Mares, A. Martí-Devesa, G. Marx, R. Maurin, G. Meintjes, P.J. Meyer, M. Moderski, R. Mohamed, M. Mohrmann, L. Montanari, A. Moore, C. Morris, P. Moulin, E. Muller, J. Murach, T. Nakashima, K. Nayerhoda, A. De Naurois, M. Ndiyavala, H. Niederwanger, F. Niemiec, J. Oakes, L. O'Brien, P. Odaka, H. Ohm, S. Olivera-Nieto, L. De Ona Wilhelmi, E. Ostrowski, M. Panter, M. Panny, S. Parsons, R.D. Peron, G. Peyaud, B. Piel, Q. Pita, S. Poireau, V. Noel, A.P. Prokhorov, D.A. Prokoph, H. Pühlhofer, G. Punch, M. Quirrenbach, A. Rauth, R. Reichherzer, P. Reimer, A. Reimer, O. Remy, Q. Renaud, M. Rieger, F. Rinchiuso, L. Romoli, C. Rowell, G. Rudak, B. Ruiz-Velasco, E. Sahakian, V. Sailer, S. Sanchez, D.A. Santangelo, A. Sasaki, M. Scalici, M. Schutte, H.M. Schwanke, U. Schwemmer, S. Seglar-Arroyo, M. Senniappan, M. Seyffert, A.S. Shafi, N. Shiningayamwe, K. Simoni, R. Sinha, A. Sol, H. Specovius, A. Spencer, S. Spir-Jacob, M. Stawarz, Ł. Sun, L. Steenkamp, R. Stegmann, C. Steinmassl, S. Steppa, C. Takahashi, T. Tavernier, T. Taylor, A.M. Terrier, R. Tiziani, D. Tluczykont, M. Tomankova, L. Trichard, C. Tsirou, M. Tuffs, R. Uchiyama, Y. Van Der Walt, D.J. Van Eldik, C. Van Rensburg, C. Van Soelen, B. Vasileiadis, G. Veh, J. Venter, C. Vincent, P. Vink, J. Völk, H.J. Vuillaume, T. Wadiasingh, Z. Wagner, S.J. Watson, J. Werner, F. White, R. Wierzcholska, A. Wong, Y.W. Yusafzai, A. Zacharias, M. Zanin, R. Zargaryan, D. Zdziarski, A.A. Zech, A. Zhu, S.J. Zorn, J. Zouari, S. Żywucka, N. Acciari, V.A. Ansoldi, S. Antonelli, L.A. Engels, A.A. Artero, M. Asano, K. Baack, D. Babić, A. Baquero, A. De Almeida, U.B. Barrio, J.A. Becerra González, J. Bednarek, W. Bellizzi, L. Bernardini, E. Bernardos, M. Berti, A. Besenrieder, J. Bhattacharyya, W. Bigongiari, C. Biland, A. Blanch, O. Bonnoli, G. Bošnjak, Ž. Busetto, G. Carosi, R. Ceribella, G. Cerruti, M. Chai, Y. Chilingarian, A. Cikota, S. Colak, S.M. Colombo, E. Contreras, J.L. Cortina, J. Covino, S. D'Amico, G. D'Elia, V. Da Vela, P. Dazzi, F. De Angelis, A. De Lotto, B. Delfino, M. Delgado, J. Delgado Mendez, C. Depaoli, D. Di Pierro, F. Di Venere, L. Do Souto Espineira, E. Dominis Prester, D. Donini, A. Dorner, D. Doro, M. Elsaesser, D. Fallah Ramazani, V. Fattorini, A. Ferrara, G. Fonseca, M.V. Font, L. Fruck, C. Fukami, S. García López, R.J. Garczarczyk, M. Gasparyan, S. Gaug, M. Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. Green, J.G. Green, D. Hadasch, D. Hahn, A. Heckmann, L. Herrera, J. Hoang, J. Hrupec, D. Hütten, M. Inada, T. Inoue, S. Ishio, K. Iwamura, Y. Jiménez, I. Jormanainen, J. Jouvin, L. Kajiwara, Y. Karjalainen, M. Kerszberg, D. Kobayashi, Y. Kubo, H. Kushida, J. Lamastra, A. Lelas, D. Leone, F. Lindfors, E. Lombardi, S. Longo, F. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Machado De Oliveira Fraga, B. Maggio, C. Majumdar, P. Makariev, M. Mallamaci, M. Maneva, G. Manganaro, M. Mannheim, K. Maraschi, L. Mariotti, M. Martínez, M. Mazin, D. Menchiari, S. Mender, S. Mićanović, S. Miceli, D. Miener, T. Minev, M. Miranda, J.M. Mirzoyan, R. Molina, E. Moralejo, A. Morcuende, D. Moreno, V. Moretti, E. Neustroev, V. Nigro, C. Nilsson, K. Nishijima, K. Noda, K. Nozaki, S. Ohtani, Y. Oka, T. Otero-Santos, J. Paiano, S. Palatiello, M. Paneque, D. Paoletti, R. Paredes, J.M. Pavletić, L. Penil, P. Perennes, C. Persic, M. Moroni, P.G.P. Prandini, E. Priyadarshi, C. Puljak, I. Rhode, W. Ribó, M. Rico, J. Righi, C. Rugliancich, A. Saha, L. Sahakyan, N. Saito, T. Sakurai, S. Satalecka, K. Saturni, F.G. Schleicher, B. Schmidt, K. Schweizer, T. Sitarek, J. Šnidarić, I. Sobczynska, D. Spolon, A. Stamerra, A. Strom, D. Strzys, M. Suda, Y. Surić, T. Takahashi, M. Tavecchio, F. Temnikov, P. Terzić, T. Teshima, M. Tosti, L. Truzzi, S. Tutone, A. Ubach, S. Van Scherpenberg, J. Vanzo, G. Vazquez Acosta, M. Ventura, S. Verguilov, V. Vigorito, C.F. Vitale, V. Vovk, I. Will, M. Wunderlich, C. Zarić, D. Adams, C.B. Benbow, W. Brill, A. Capasso, M. Christiansen, J.L. Chromey, A.J. Daniel, M.K. Errando, M. Farrell, K.A. Feng, Q. Finley, J.P. Fortson, L. Furniss, A. Gent, A. Giuri, C. Hassan, T. Hervet, O. Holder, J. Hughes, G. Humensky, T.B. Jin, W. Kaaret, P. Kertzman, M. Kieda, D. Kumar, S. Lang, M.J. Lundy, M. Maier, G. Moriarty, P. Mukherjee, R. Nieto, D. Nievas-Rosillo, M. O'Brien, S. Ong, R.A. Otte, A.N. Patel, S. Pfrang, K. Pohl, M. Prado, R.R. Pueschel, E. Quinn, J. Ragan, K. Reynolds, P.T. Ribeiro, D. Richards, G.T. Roache, E. Rulten, C. Ryan, J.L. Santander, M. Sembroski, G.H. Shang, R. Weinstein, A. Williams, D.A. Williamson, T.J. Hirota, T. Cui, L. Niinuma, K. Ro, H. Sakai, N. Sawada-Satoh, S. Wajima, K. Wang, N. Liu, X. Yonekura, Y.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded. © 2021. The Author(s). Published by the American Astronomical Society..

Published
2021

22. Constraints on black-hole charges with the 2017 EHT observations of M87∗

Author

Kocherlakota, P. Rezzolla, L. Falcke, H. Fromm, C.M. Kramer, M. Mizuno, Y. Nathanail, A. Olivares, H. Younsi, Z. Akiyama, K. Alberdi, A. Alef, W. Algaba, J.C. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Baloković, M. Barrett, J. Benson, B.A. Bintley, D. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Doeleman, S.S. Eatough, R.P. Farah, J. Fish, V.L. Fomalont, E. Fraga-Encinas, R. Friberg, P. Ford, H.A. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Goddi, C. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, C. Krichbaum, T.P. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. Macdonald, N.R. Mao, J. Marchili, N. Markoff, S. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Neilsen, J. Neri, R. Ni, C. Noutsos, A. Nowak, M.A. Okino, H. Ortiz-León, G.N. Oyama, T. Özel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Ramakrishnan, V. Rao, R. Rawlings, M.G. Raymond, A.W. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Van Bemmel, I. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. (EHT Collaboration)

Subjects
General Relativity and Quantum Cosmology, Astrophysics::High Energy Astrophysical Phenomena
Abstract

Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87∗ shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show that the quality of the measurements is already sufficient to rule out that M87∗ is a highly charged dilaton black hole. Similarly, when considering black holes with two physical and independent charges, we are able to exclude considerable regions of the space of parameters for the doubly-charged dilaton and the Sen black holes. © 2021 authors. Published by the American Physical Society.

Published
2021

23. Event Horizon Telescope observations of the jet launching and collimation in Centaurus A

Author

Janssen, M. Falcke, H. Kadler, M. Ros, E. Wielgus, M. Akiyama, K. Baloković, M. Blackburn, L. Bouman, K.L. Chael, A. Chan, C.-K. Chatterjee, K. Davelaar, J. Edwards, P.G. Fromm, C.M. Gómez, J.L. Goddi, C. Issaoun, S. Johnson, M.D. Kim, J. Koay, J.Y. Krichbaum, T.P. Liu, J. Liuzzo, E. Markoff, S. Markowitz, A. Marrone, D.P. Mizuno, Y. Müller, C. Ni, C. Pesce, D.W. Ramakrishnan, V. Roelofs, F. Rygl, K.L.J. van Bemmel, I. Alberdi, A. Alef, W. Algaba, J.C. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Barrett, J. Benson, B.A. Bintley, D. Blundell, R. Boland, W. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chatterjee, S. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gelles, Z. Gentaz, O. Georgiev, B. Gold, R. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Himwich, E. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. James, D.J. Jannuzi, B.T. Jeter, B. Jiang, W. Jimenez-Rosales, A. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kino, M. Kofuji, Y. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, K. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. MacDonald, N.R. Mao, J. Marchili, N. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Moran, J.M. Moriyama, K. Moscibrodzka, M. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neilsen, J. Neri, R. Noutsos, A. Nowak, M.A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. Özel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Piétu, V. Plambeck, R. PopStefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Rogers, A. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. SooHoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Torne, P. Trent, T. Traianou, E. Trippe, S. van Bemmel, I. van Langevelde, H.J. van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. The Event Horizon Telescope Collaboration

Abstract

Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimetre wavelengths have the power to reveal the launching and initial collimation region of extragalactic radio jets, down to 10–100 gravitational radii (rg ≡ GM/c2) scales in nearby sources1. Centaurus A is the closest radio-loud source to Earth2. It bridges the gap in mass and accretion rate between the supermassive black holes (SMBHs) in Messier 87 and our Galactic Centre. A large southern declination of −43° has, however, prevented VLBI imaging of Centaurus A below a wavelength of 1 cm thus far. Here we show the millimetre VLBI image of the source, which we obtained with the Event Horizon Telescope at 228 GHz. Compared with previous observations3, we image the jet of Centaurus A at a tenfold higher frequency and sixteen times sharper resolution and thereby probe sub-lightday structures. We reveal a highly collimated, asymmetrically edge-brightened jet as well as the fainter counterjet. We find that the source structure of Centaurus A resembles the jet in Messier 87 on ~500 rg scales remarkably well. Furthermore, we identify the location of Centaurus A’s SMBH with respect to its resolved jet core at a wavelength of 1.3 mm and conclude that the source’s event horizon shadow4 should be visible at terahertz frequencies. This location further supports the universal scale invariance of black holes over a wide range of masses5,6. © 2021, The Author(s).

Published
2021

24. Polarimetric Properties of Event Horizon Telescope Targets from ALMA

Author

Goddi, C. Martí-Vidal, I. Messias, H. Bower, G.C. Broderick, A.E. Dexter, J. Marrone, D.P. Moscibrodzka, M. Nagai, H. Algaba, J.C. Asada, K. Crew, G.B. Gómez, J.L. Impellizzeri, C.M.V. Janssen, M. Kadler, M. Krichbaum, T.P. Lico, R. Matthews, L.D. Nathanail, A. Ricarte, A. Ros, E. Younsi, Z. Akiyama, K. Alberdi, A. Alef, W. Anantua, R. Azulay, R. Baczko, A.-K. Ball, D. Baloković, M. Barrett, J. Benson, B.A. Bintley, D. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Cruz-Osorio, A. Cui, Y. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Freeman, W.T. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. Garciá, R. Gentaz, O. Georgiev, B. Gold, R. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. Macdonald, N.R. Mao, J. Marchili, N. Markoff, S. Marscher, A.P. Matsushita, S. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Müller, C. Musoke, G. Mejiás, A.M. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Neilsen, J. Neri, R. Ni, C. Noutsos, A. Nowak, M.A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. zel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Ramakrishnan, V. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ripperda, B. Roelofs, F. Rogers, A. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Bemmel, I.V. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. Bruni, G. Gopakumar, A. Hernández-Gómez, A. Herrero-Illana, R. Ingram, A. Komossa, S. Kovalev, Y.Y. Muders, D. Perucho, M. Rösch, F. Valtonen, M.

Abstract

We present the results from a full polarization study carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) during the first Very Long Baseline Interferometry (VLBI) campaign, which was conducted in 2017 April in the λ3 mm and λ1.3 mm bands, in concert with the Global mm-VLBI Array (GMVA) and the Event Horizon Telescope (EHT), respectively. We determine the polarization and Faraday properties of all VLBI targets, including Sgr A∗, M87, and a dozen radio-loud active galactic nuclei (AGNs), in the two bands at several epochs in a time window of 10 days. We detect high linear polarization fractions (2%-15%) and large rotation measures (RM > 103.3-105.5 rad m-2), confirming the trends of previous AGN studies at millimeter wavelengths. We find that blazars are more strongly polarized than other AGNs in the sample, while exhibiting (on average) order-of-magnitude lower RM values, consistent with the AGN viewing angle unification scheme. For Sgr A∗ we report a mean RM of (-4.2 0.3) 105 rad m-2 at 1.3 mm, consistent with measurements over the past decade and, for the first time, an RM of (-2.1 0.1) 105 rad m-2 at 3 mm, suggesting that about half of the Faraday rotation at 1.3 mm may occur between the 3 mm photosphere and the 1.3 mm source. We also report the first unambiguous measurement of RM toward the M87 nucleus at millimeter wavelengths, which undergoes significant changes in magnitude and sign reversals on a one year timescale, spanning the range from -1.2 to 0.3 105 rad m-2 at 3 mm and -4.1 to 1.5 105 rad m-2 at 1.3 mm. Given this time variability, we argue that, unlike the case of Sgr A∗, the RM in M87 does not provide an accurate estimate of the mass accretion rate onto the black hole. We put forward a two-component model, comprised of a variable compact region and a static extended region, that can simultaneously explain the polarimetric properties observed by both the EHT (on horizon scales) and ALMA (which observes the combined emission from both components). These measurements provide critical constraints for the calibration, analysis, and interpretation of simultaneously obtained VLBI data with the EHT and GMVA. © 2021. The American Astronomical Society.

Published
2021

25. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author

Algaba, J. C., Anczarski, J., Asada, K., Baloković, M., Chandra, S., Cui, Y. -Z, Falcone, A. D., Giroletti, M., Goddi, C., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Keating, G., Kim, J. -Y, Kino, M., Komossa, S., Kravchenko, E. V., Krichbaum, T. P., Lee, S. -S, Lu, R. -S, Lucchini, M., Markoff, S., Neilsen, J., Nowak, M. A., Park, J., Principe, G., Ramakrishnan, V., Reynolds, M. T., Sasada, M., Savchenko, S. S., Williamson, K. E., Akiyama, K., Alberdi, A., Alef, W., Anantua, R., Azulay, R., Baczko, A. -K, Ball, D., Barrett, J., Bintley, D., Benson, B. A., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y, Carlstrom, J. E., Chael, A., Chan, C. -K, Chatterjee, S., Chatterjee, K., Chen, M. -T, Chen, Y., Chesler, P. M., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Gold, R., Gómez, J. L., Gómez-Ruiz, A. I., Gu, M., Gurwell, M., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -WL., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jiménez-Rosales, A., Johnson, M. D., Jung, T., Karami, M., Karuppusamy, R., Kettenis, M., Kim, D. -J, Kim, J., Koay, J. Y., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Kuo, C. -Y, Lauer, T. R., Levis, A., Li, Y. -R, Li, Z., Lindqvist, M., Lico, R., Lindahl, G., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P, Lobanov, A. P., Loinard, L., Lonsdale, C., Macdonald, N. 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W., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., Å»ywucka, N., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., De Almeida, U. B., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., BoÅ¡njak, Åœ., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Amico, G., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espineira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., HÃŒtten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jiménez, I., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Penil, P., Perennes, C., Persic, M., Moroni, P. G. P., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Å nidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zarić, D., Adams, C. B., Benbow, W., Brill, A., Capasso, M., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Errando, M., Farrell, K. A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Giuri, C., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kieda, D., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O’Brien, S., Ong, R. A., Otte, A. N., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Rulten, C., Ryan, J. L., Santander, M., Sembroski, G. H., Shang, R., Weinstein, A., Williams, D. A., Williamson, T. J., Hirota, T., Cui, L., Niinuma, K., Ro, H., Sakai, N., Sawada-Satoh, S., Wajima, K., Wang, N., Liu, X., and Yonekura, Y.

Abstract

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∌6.5 × 109 M oË™. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded. © 2021. The Author(s). Published by the American Astronomical Society..

Published
2021
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26. SYMBA: An end-to-end VLBI synthetic data generation pipeline: Simulating Event Horizon Telescope observations of M 87

Author

Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Roelofs, Freek, Janssen, M., Natarajan, I., Deane, Roger, Davelaar, J., Olivares, H., Porth, O., Paine, S. N., Bouman, Katherine L., Tilanus, R. P. J., van Bemmel, I. M., Schuster, K., Goddi, Ciriaco, Broderick, Avery E., Koay, J.Y, Ramakrishnan, V., Lobanov, A.P., Rawlings, M. G., Asada, Keiichi, Sánchez-Arguelles, D., Wong, G. N., Kim, J., Baloković, M., Roshanineshat, A., Ball, D., Hesper, R., Chatterjee, K., Titus, Michael A., Akiyama, Kazunori, Ruszczyk, Chester A., Inoue, M., Lee, S., Sasada, Mahito, Broguiere, D., Tazaki, F., Conway, J.E, Weintroub, Jonathan, Savolainen, T., Karuppusamy, R., MacDonald, N.R., Wagner, J., Young, K., Won Sohn, B., Noutsos, A., Medeiros, L., Barrett, John, van Langevelde, H. J., Zhao, Shan-Shan, Koch, P. M., Gentaz, O., Alberdi, Antxón, Ortiz-León, G. N., Wardle, J., Li, Z., Yuan, Y., Fraga-Encinas, R., Wu, Q., Fomalont, E., Falcke, H., Hada, Kazuhiro, Brinkerink, C. D., Young, A., Mao, J., Neri, Roberto, Bower, G.C., Ho, P., Chan, C., Zhao, G., Rogers, A., Patel, Nimesh, Carlstrom, J.E, Blackburn, Lindy, Christian, P., Mizuno, I., Kawashima, T., Preciado-López, J.A, Boland, W., Rottmann, H., Bremer, M., Ikeda, S., Chen, M., Jannuzi, B.T, Bronzwaer, T., James, D.J, Müller, C., Kino, Motoki, Dexter, J., Huang, C. L., Chael, A., Ni, C., Rezzolla, L., Dempsey, J., Kramer, C., Gammie, C.F, Cho, I., Trent, T., Rygl, K. L. J., Gómez, José L., Gu, M., Cui, Y., Gurwell, M., Piétu, V., Markoff, S., Shen, Z., De Laurentis, M., van Rossum, D. R., Desvignes, Gregory, Li, Y., Georgiev, B., Keating, G.K, Liu, K., Friberg, P., Lico, Rocco, Psaltis, D., Menten, K. M., Huang, L., Kuo, C., Galison, P., Ripperda, B., Toma, K., Marrone, Daniel P., Honma, M., Moscibrodzka, M., Jung, T., Gold, R., Baczko, A., Wex, N., Johnson, M. D., Ho, L. C., Younsi, Z., Liuzzo, Elisabetta, Jeter, B., Kramer, M., Small, D., Pen, U., Lauer, T.R, Byun, D., Jorstad, S., Traianou, E., Alef, W., Kettenis, Mark, Okino, H., Krichbaum, Thomas P., Prather, B., Lu, R., Wharton, R., Brissenden, R., Loinard, Laurent, Matthews, L.D., Koyama, S., Fish, Vincent L., Chatterjee, S., Martí-Vidal, Iván, Lo, W., Moriyama, K., Zensus, J. A., Sánchez, S., Cordes, J.M., Fromm, Christian M., Lonsdale, Colin J., Azulay, Rebecca, Mizuno, Y., Rose, M., Marscher, Alan P., Ros, E., Bintley, D., Shao, L., Narayanan, Gopal, Matsushita, S., Britzen, S., Doeleman, Sheperd S., Nakamura, M., SooHoo, J., Palumbo, Daniel C. M., Morán, J.M., Issaoun, Sara, García, R., Oyama, T., Nagai, H., PopStefanija, A., Chen, Y., Wielgus, Maciek, Hecht, M.H, Nagar, Neil M., Jiang, Wu, Narayan, Ramesh, Torne, P., Pesce, Dominic W., Tsuda, S., Trippe, S., Crew, Geoffrey B., Yuan, F., Raymond, Alexander W., Tiede, Paul, Özel, F., Eatough, R. P., Hughes, D. H., Rao, R., Zhu, Z., Ryan, B. R., Plambeck, R., Lindqvist, M., Karami, M., Roy, A.L., Schloerb, F. P., Pu, H., Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Roelofs, Freek, Janssen, M., Natarajan, I., Deane, Roger, Davelaar, J., Olivares, H., Porth, O., Paine, S. N., Bouman, Katherine L., Tilanus, R. P. J., van Bemmel, I. M., Schuster, K., Goddi, Ciriaco, Broderick, Avery E., Koay, J.Y, Ramakrishnan, V., Lobanov, A.P., Rawlings, M. G., Asada, Keiichi, Sánchez-Arguelles, D., Wong, G. N., Kim, J., Baloković, M., Roshanineshat, A., Ball, D., Hesper, R., Chatterjee, K., Titus, Michael A., Akiyama, Kazunori, Ruszczyk, Chester A., Inoue, M., Lee, S., Sasada, Mahito, Broguiere, D., Tazaki, F., Conway, J.E, Weintroub, Jonathan, Savolainen, T., Karuppusamy, R., MacDonald, N.R., Wagner, J., Young, K., Won Sohn, B., Noutsos, A., Medeiros, L., Barrett, John, van Langevelde, H. J., Zhao, Shan-Shan, Koch, P. M., Gentaz, O., Alberdi, Antxón, Ortiz-León, G. N., Wardle, J., Li, Z., Yuan, Y., Fraga-Encinas, R., Wu, Q., Fomalont, E., Falcke, H., Hada, Kazuhiro, Brinkerink, C. D., Young, A., Mao, J., Neri, Roberto, Bower, G.C., Ho, P., Chan, C., Zhao, G., Rogers, A., Patel, Nimesh, Carlstrom, J.E, Blackburn, Lindy, Christian, P., Mizuno, I., Kawashima, T., Preciado-López, J.A, Boland, W., Rottmann, H., Bremer, M., Ikeda, S., Chen, M., Jannuzi, B.T, Bronzwaer, T., James, D.J, Müller, C., Kino, Motoki, Dexter, J., Huang, C. L., Chael, A., Ni, C., Rezzolla, L., Dempsey, J., Kramer, C., Gammie, C.F, Cho, I., Trent, T., Rygl, K. L. J., Gómez, José L., Gu, M., Cui, Y., Gurwell, M., Piétu, V., Markoff, S., Shen, Z., De Laurentis, M., van Rossum, D. R., Desvignes, Gregory, Li, Y., Georgiev, B., Keating, G.K, Liu, K., Friberg, P., Lico, Rocco, Psaltis, D., Menten, K. M., Huang, L., Kuo, C., Galison, P., Ripperda, B., Toma, K., Marrone, Daniel P., Honma, M., Moscibrodzka, M., Jung, T., Gold, R., Baczko, A., Wex, N., Johnson, M. D., Ho, L. C., Younsi, Z., Liuzzo, Elisabetta, Jeter, B., Kramer, M., Small, D., Pen, U., Lauer, T.R, Byun, D., Jorstad, S., Traianou, E., Alef, W., Kettenis, Mark, Okino, H., Krichbaum, Thomas P., Prather, B., Lu, R., Wharton, R., Brissenden, R., Loinard, Laurent, Matthews, L.D., Koyama, S., Fish, Vincent L., Chatterjee, S., Martí-Vidal, Iván, Lo, W., Moriyama, K., Zensus, J. A., Sánchez, S., Cordes, J.M., Fromm, Christian M., Lonsdale, Colin J., Azulay, Rebecca, Mizuno, Y., Rose, M., Marscher, Alan P., Ros, E., Bintley, D., Shao, L., Narayanan, Gopal, Matsushita, S., Britzen, S., Doeleman, Sheperd S., Nakamura, M., SooHoo, J., Palumbo, Daniel C. M., Morán, J.M., Issaoun, Sara, García, R., Oyama, T., Nagai, H., PopStefanija, A., Chen, Y., Wielgus, Maciek, Hecht, M.H, Nagar, Neil M., Jiang, Wu, Narayan, Ramesh, Torne, P., Pesce, Dominic W., Tsuda, S., Trippe, S., Crew, Geoffrey B., Yuan, F., Raymond, Alexander W., Tiede, Paul, Özel, F., Eatough, R. P., Hughes, D. H., Rao, R., Zhu, Z., Ryan, B. R., Plambeck, R., Lindqvist, M., Karami, M., Roy, A.L., Schloerb, F. P., and Pu, H.

Abstract

Context. Realistic synthetic observations of theoretical source models are essential for our understanding of real observational data. In using synthetic data, one can verify the extent to which source parameters can be recovered and evaluate how various data corruption effects can be calibrated. These studies are the most important when proposing observations of new sources, in the characterization of the capabilities of new or upgraded instruments, and when verifying model-based theoretical predictions in a direct comparison with observational data. Aims. We present the SYnthetic Measurement creator for long Baseline Arrays (SYMBA), a novel synthetic data generation pipeline for Very Long Baseline Interferometry (VLBI) observations. SYMBA takes into account several realistic atmospheric, instrumental, and calibration effects. Methods. We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a millimetre VLBI array, which has recently captured the first image of a black hole shadow. After testing SYMBA with simple source and corruption models, we study the importance of including all corruption and calibration effects, compared to the addition of thermal noise only. Using synthetic data based on two example general relativistic magnetohydrodynamics (GRMHD) model images of M 87, we performed case studies to assess the image quality that can be obtained with the current and future EHT array for different weather conditions. Results. Our synthetic observations show that the effects of atmospheric and instrumental corruptions on the measured visibilities are significant. Despite these effects, we demonstrate how the overall structure of our GRMHD source models can be recovered robustly with the EHT2017 array after performing calibration steps, which include fringe fitting, a priori amplitude and network calibration, and self-calibration. With the planned addition of new stations to the EHT array in the coming years, images could be reconstr

Published
2020

27. SYMBA: An end-to-end VLBI synthetic data generation pipeline

Author

Roelofs, F., primary, Janssen, M., additional, Natarajan, I., additional, Deane, R., additional, Davelaar, J., additional, Olivares, H., additional, Porth, O., additional, Paine, S. N., additional, Bouman, K. L., additional, Tilanus, R. P. J., additional, van Bemmel, I. M., additional, Falcke, H., additional, Akiyama, K., additional, Alberdi, A., additional, Alef, W., additional, Asada, K., additional, Azulay, R., additional, Baczko, A., additional, Ball, D., additional, Baloković, M., additional, Barrett, J., additional, Bintley, D., additional, Blackburn, L., additional, Boland, W., additional, Bower, G. C., additional, Bremer, M., additional, Brinkerink, C. D., additional, Brissenden, R., additional, Britzen, S., additional, Broderick, A. E., additional, Broguiere, D., additional, Bronzwaer, T., additional, Byun, D., additional, Carlstrom, J. E., additional, Chael, A., additional, Chan, C., additional, Chatterjee, S., additional, Chatterjee, K., additional, Chen, M., additional, Chen, Y., additional, Cho, I., additional, Christian, P., additional, Conway, J. E., additional, Cordes, J. M., additional, Crew, G. B., additional, Cui, Y., additional, De Laurentis, M., additional, Dempsey, J., additional, Desvignes, G., additional, Dexter, J., additional, Doeleman, S. S., additional, Eatough, R. P., additional, Fish, V. L., additional, Fomalont, E., additional, Fraga-Encinas, R., additional, Friberg, P., additional, Fromm, C. M., additional, Gómez, J. L., additional, Galison, P., additional, Gammie, C. F., additional, García, R., additional, Gentaz, O., additional, Georgiev, B., additional, Goddi, C., additional, Gold, R., additional, Gu, M., additional, Gurwell, M., additional, Hada, K., additional, Hecht, M. H., additional, Hesper, R., additional, Ho, L. C., additional, Ho, P., additional, Honma, M., additional, Huang, C. L., additional, Huang, L., additional, Hughes, D. H., additional, Ikeda, S., additional, Inoue, M., additional, Issaoun, S., additional, James, D. J., additional, Jannuzi, B. T., additional, Jeter, B., additional, Jiang, W., additional, Johnson, M. D., additional, Jorstad, S., additional, Jung, T., additional, Karami, M., additional, Karuppusamy, R., additional, Kawashima, T., additional, Keating, G. K., additional, Kettenis, M., additional, Kim, J., additional, Kino, M., additional, Koay, J. Y., additional, Koch, P. M., additional, Koyama, S., additional, Kramer, M., additional, Kramer, C., additional, Krichbaum, T. P., additional, Kuo, C., additional, Lauer, T. R., additional, Lee, S., additional, Li, Y., additional, Li, Z., additional, Lindqvist, M., additional, Lico, R., additional, Liu, K., additional, Liuzzo, E., additional, Lo, W., additional, Lobanov, A. P., additional, Loinard, L., additional, Lonsdale, C., additional, Lu, R., additional, MacDonald, N. R., additional, Mao, J., additional, Markoff, S., additional, Marrone, D. P., additional, Marscher, A. P., additional, Martí-Vidal, I., additional, Matsushita, S., additional, Matthews, L. D., additional, Medeiros, L., additional, Menten, K. M., additional, Mizuno, Y., additional, Mizuno, I., additional, Moran, J. M., additional, Moriyama, K., additional, Moscibrodzka, M., additional, Müller, C., additional, Nagai, H., additional, Nagar, N. M., additional, Nakamura, M., additional, Narayan, R., additional, Narayanan, G., additional, Neri, R., additional, Ni, C., additional, Noutsos, A., additional, Okino, H., additional, Ortiz-León, G. N., additional, Oyama, T., additional, Özel, F., additional, Palumbo, D. C. M., additional, Patel, N., additional, Pen, U., additional, Pesce, D. W., additional, Piétu, V., additional, Plambeck, R., additional, PopStefanija, A., additional, Prather, B., additional, Preciado-López, J. A., additional, Psaltis, D., additional, Pu, H., additional, Ramakrishnan, V., additional, Rao, R., additional, Rawlings, M. G., additional, Raymond, A. W., additional, Rezzolla, L., additional, Ripperda, B., additional, Rogers, A., additional, Ros, E., additional, Rose, M., additional, Roshanineshat, A., additional, Rottmann, H., additional, Roy, A. L., additional, Ruszczyk, C., additional, Ryan, B. R., additional, Rygl, K. L. J., additional, Sánchez, S., additional, Sánchez-Arguelles, D., additional, Sasada, M., additional, Savolainen, T., additional, Schloerb, F. P., additional, Schuster, K., additional, Shao, L., additional, Shen, Z., additional, Small, D., additional, Won Sohn, B., additional, SooHoo, J., additional, Tazaki, F., additional, Tiede, P., additional, Titus, M., additional, Toma, K., additional, Torne, P., additional, Traianou, E., additional, Trent, T., additional, Trippe, S., additional, Tsuda, S., additional, van Langevelde, H. J., additional, van Rossum, D. R., additional, Wagner, J., additional, Wardle, J., additional, Weintroub, J., additional, Wex, N., additional, Wharton, R., additional, Wielgus, M., additional, Wong, G. N., additional, Wu, Q., additional, Young, A., additional, Young, K., additional, Younsi, Z., additional, Yuan, F., additional, Yuan, Y., additional, Zensus, J. A., additional, Zhao, G., additional, Zhao, S., additional, and Zhu, Z., additional

Published
2020
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28. General-relativistic Resistive Magnetohydrodynamics with Robust Primitive-variable Recovery for Accretion Disk Simulations

Author

Ripperda, B. (Bart), Bacchini1, F. (Fabio), Porth, O. (Oliver), Most, E.R. (Elias), Olivares, H. (Hector), Nathanail, A. (Antonios), Rezzolla, L. (Luciano), Teunissen, H.J. (Jannis), Keppens, R. (Rony), Ripperda, B. (Bart), Bacchini1, F. (Fabio), Porth, O. (Oliver), Most, E.R. (Elias), Olivares, H. (Hector), Nathanail, A. (Antonios), Rezzolla, L. (Luciano), Teunissen, H.J. (Jannis), and Keppens, R. (Rony)

Abstract

Recent advances in black hole astrophysics, particularly the first visual evidence of a supermassive black hole at the center of the galaxy M87 by the Event Horizon Telescope, and the detection of an orbiting "hot spot" nearby the event horizon of Sgr A* in the Galactic center by the Gravity Collaboration, require the development of novel numerical methods to understand the underlying plasma microphysics. Non-thermal emission related to such hot spots is conjectured to originate from plasmoids that form due to magnetic reconnection in thin current layers in the innermost accretion zone. Resistivity plays a crucial role in current sheet formation, magnetic reconnection, and plasmoid growth in black hole accretion disks and jets. We included resistivity in the three-dimensional general-relativistic magnetohydrodynamics (GRMHD) code BHAC and present the implementation of an implicit–explicit scheme to treat the stiff resistive source terms of the GRMHD equations. The algorithm is tested in combination with adaptive mesh refinement to resolve the resistive scales and a constrained transport method to keep the magnetic field solenoidal. Several novel methods for primitive-variable recovery, a key part in relativistic magnetohydrodynamics codes, are presented and compared for accuracy, robustness, and efficiency. We propose a new inversion strategy that allows for resistive-GRMHD simulations of low gas-to-magnetic pressure ratio and highly magnetized regimes as applicable for black hole accretion disks, jets, and neutron-star magnetospheres. We apply the new scheme to study the effect of resistivity on accreting black holes, accounting for dissipative effects as reconnection.

Published
2019

29. The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project

Author

National Science Foundation (US), Netherlands Organization for Scientific Research, European Research Council, Gauss Centre for Supercomputing, Department of Energy (US), Academy of Finland, European Commission, John Templeton Foundation, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), Universidad Nacional Autónoma de México, Generalitat Valenciana, Gordon and Betty Moore Foundation, National Radio Astronomy Observatory (US), Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Leverhulme Trust, MIT International Science and Technology Initiatives, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Key Research and Development Program (China), National Research Foundation of Korea, Spinoza Prize, South African Radio Astronomy Observatory, Swedish Research Council, Government of Canada, Russian Science Foundation, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministero dell'Istruzione, dell'Università e della Ricerca, Chandra X-ray Observatory, CyVerse, Compute Ontario, Calcul Québec, Compute Canada, Porth, O., Chatterjee, K., Narayan, Ramesh, Gammie, C.F, Mizuno, Yosuke, Anninos, P., Baker, J. G., Bugli, M, Chan, C. K., Davelaar, J., Zanna, L. D., Zensus, J. A., Tilanus, R. P. J., Koay, J. Y., Young, K., Boland, W., Gentaz, O., Rao, R., Kino, Motoki, Nagar, Neil M., Rygl, K. L. J., Matthews, L. D., Palumbo, Daniel C. M., Ros, E., Psaltis, D, Medeiros, L., Jiang, Wu, Natarajan, I., Fish, Vincent L., Honma, M., Lauer, T. R., Schuster, K. F., Koch, P. M., Zhao, G., Issaoun, Sara, Roy, A. L., Schloerb, F. P., Kim, J., Azulay, Rebecca, Akiyama, Kazunori, Oyama, T., Alberdi, Antxón, Wagner, J., Stone, J. M., Menten, K. M., Ripperda, B., Narayanan, Gopal, Karuppusamy, R., Piétu, V., Broguiere, D., Roelofs, Freek, Noble, S. C., Baczko, A. K., Ball, D., Yuan, Y. F., Sánchez-Arguelles, D., Wu, Q., Ho, P., Lindqvist, M., Koyama, S., Sánchez, S., Keating, G. K., Plambeck, R., Li, Y. R., Kelly, B. J., Markoff, S., Kramer, Michael, van Rossum, D. R., Marscher, Alan P., Yuan, F., Patel, Nimesh, Wardle, J., Alef, W., Lobanov, A. P., Rezzolla, L., PopStefanija, A., Bintley, D, Conway, J. E., van Langevelde, H. J., Bremer, M., Sasada, Mahito, Moscibrodzka, M., Toma, K., Raymond, A. W., Wielgus, Maciek, Titus, Michael A., Hecht, M. H., Rogers, A., Fomalont, E., Carlstrom, J. E., Savolainen, T., Britzen, S., Loinard, Laurent, Özel, F., Nagai, H., Zhao, Shan-Shan, Brinkerink, C. D., Ryan, B. R., Trent, T., Jannuzi, B. T., SooHoo, J., Tiede, Paul, Ikeda, S., Lo, W. P., McKinney, J. C., Byun, D. Y., Tazaki, F., Crew, Geoffrey B., De Laurentis, M., Blackburn, Lindy, Chen, Y., Pesce, Dominic W., Broderick, Avery E., Trippe, S., Deane, Roger, Inoue, M., Baloković, M., Tsuda, S, Doeleman, Sheperd S., Janssen, M., Rottmann, H., Rose, M., Falcke, H., Preciado-López, J. A, Lee, S.-S, Kramer, C., Wong, G. N., Krichbaum, Thomas P., Hesper, R., Fragile, P. C., Chael, A., Mishra, B., Shao, L., Gómez, José L., Marrone, Daniel P., Gurwell, M., Kim, J. Y., Christian, P., Neri, Roberto, Friberg, P., Hughes, D. H., Gu, M., Chatterjee, S., Zhu, Z., Desvignes, Gregory, Shen, Z., Wex, N., Prather, B., Karami, M., Tomei, N., Hada, Kazuhiro, Young, A., James, D. J., Kawashima, T., Olivares, Hector, Ni, C., Kuo, C. Y., Fraga-Encinas, R., Etienne, Z. B., Liu, K., Moriyama, K., Chen, M. T., Lonsdale, Colin J., Dempsey, J., Liska, M., García, Roberto, Ramakrishnan, V., Huang, C. W. L., Galison, P., Noutsos, A., Okino, H., Matsushita, S., Johnson, M. D., MacDonald, N. R., Wharton, R., Barrett, John, White, C.J, Jeter, B., Lu, Ru-Sen, Georgiev, B., Ruszczyk, Chester A., Freeman, B., Eatough, R. P., Younsi, Z., Weintroub, Jonathan, Bronzwaer, T., Martí-Vidal, Iván, Fromm, Christian M., Müller, C., Liuzzo, Elisabetta, Mizuno, I., Bouman, Katherine L., Mao, J., Goddi, Ciriaco, Nakamura, M., Roshanineshat, A., Li, Z., Gold, R., Jorstad, S., Cordes, J. M., Cho, I., Ho, Luis C., Brissenden, R., van Bemmel, I., Torne, P., Huang, L., Small, D., Rawlings, M. G., Jung, T., Kettenis, Mark, Bower, G. C., Pen, U. L., Cui, Y., Pu, H. Y., Sohn, B. W., Morán, J. M., Asada, Keiichi, National Science Foundation (US), Netherlands Organization for Scientific Research, European Research Council, Gauss Centre for Supercomputing, Department of Energy (US), Academy of Finland, European Commission, John Templeton Foundation, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), Universidad Nacional Autónoma de México, Generalitat Valenciana, Gordon and Betty Moore Foundation, National Radio Astronomy Observatory (US), Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Leverhulme Trust, MIT International Science and Technology Initiatives, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Key Research and Development Program (China), National Research Foundation of Korea, Spinoza Prize, South African Radio Astronomy Observatory, Swedish Research Council, Government of Canada, Russian Science Foundation, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Ministero dell'Istruzione, dell'Università e della Ricerca, Chandra X-ray Observatory, CyVerse, Compute Ontario, Calcul Québec, Compute Canada, Porth, O., Chatterjee, K., Narayan, Ramesh, Gammie, C.F, Mizuno, Yosuke, Anninos, P., Baker, J. G., Bugli, M, Chan, C. K., Davelaar, J., Zanna, L. D., Zensus, J. A., Tilanus, R. P. J., Koay, J. Y., Young, K., Boland, W., Gentaz, O., Rao, R., Kino, Motoki, Nagar, Neil M., Rygl, K. L. J., Matthews, L. D., Palumbo, Daniel C. M., Ros, E., Psaltis, D, Medeiros, L., Jiang, Wu, Natarajan, I., Fish, Vincent L., Honma, M., Lauer, T. R., Schuster, K. F., Koch, P. M., Zhao, G., Issaoun, Sara, Roy, A. L., Schloerb, F. P., Kim, J., Azulay, Rebecca, Akiyama, Kazunori, Oyama, T., Alberdi, Antxón, Wagner, J., Stone, J. M., Menten, K. M., Ripperda, B., Narayanan, Gopal, Karuppusamy, R., Piétu, V., Broguiere, D., Roelofs, Freek, Noble, S. C., Baczko, A. K., Ball, D., Yuan, Y. F., Sánchez-Arguelles, D., Wu, Q., Ho, P., Lindqvist, M., Koyama, S., Sánchez, S., Keating, G. K., Plambeck, R., Li, Y. R., Kelly, B. J., Markoff, S., Kramer, Michael, van Rossum, D. R., Marscher, Alan P., Yuan, F., Patel, Nimesh, Wardle, J., Alef, W., Lobanov, A. P., Rezzolla, L., PopStefanija, A., Bintley, D, Conway, J. E., van Langevelde, H. J., Bremer, M., Sasada, Mahito, Moscibrodzka, M., Toma, K., Raymond, A. W., Wielgus, Maciek, Titus, Michael A., Hecht, M. H., Rogers, A., Fomalont, E., Carlstrom, J. E., Savolainen, T., Britzen, S., Loinard, Laurent, Özel, F., Nagai, H., Zhao, Shan-Shan, Brinkerink, C. D., Ryan, B. R., Trent, T., Jannuzi, B. T., SooHoo, J., Tiede, Paul, Ikeda, S., Lo, W. P., McKinney, J. C., Byun, D. Y., Tazaki, F., Crew, Geoffrey B., De Laurentis, M., Blackburn, Lindy, Chen, Y., Pesce, Dominic W., Broderick, Avery E., Trippe, S., Deane, Roger, Inoue, M., Baloković, M., Tsuda, S, Doeleman, Sheperd S., Janssen, M., Rottmann, H., Rose, M., Falcke, H., Preciado-López, J. A, Lee, S.-S, Kramer, C., Wong, G. N., Krichbaum, Thomas P., Hesper, R., Fragile, P. C., Chael, A., Mishra, B., Shao, L., Gómez, José L., Marrone, Daniel P., Gurwell, M., Kim, J. Y., Christian, P., Neri, Roberto, Friberg, P., Hughes, D. H., Gu, M., Chatterjee, S., Zhu, Z., Desvignes, Gregory, Shen, Z., Wex, N., Prather, B., Karami, M., Tomei, N., Hada, Kazuhiro, Young, A., James, D. J., Kawashima, T., Olivares, Hector, Ni, C., Kuo, C. Y., Fraga-Encinas, R., Etienne, Z. B., Liu, K., Moriyama, K., Chen, M. T., Lonsdale, Colin J., Dempsey, J., Liska, M., García, Roberto, Ramakrishnan, V., Huang, C. W. L., Galison, P., Noutsos, A., Okino, H., Matsushita, S., Johnson, M. D., MacDonald, N. R., Wharton, R., Barrett, John, White, C.J, Jeter, B., Lu, Ru-Sen, Georgiev, B., Ruszczyk, Chester A., Freeman, B., Eatough, R. P., Younsi, Z., Weintroub, Jonathan, Bronzwaer, T., Martí-Vidal, Iván, Fromm, Christian M., Müller, C., Liuzzo, Elisabetta, Mizuno, I., Bouman, Katherine L., Mao, J., Goddi, Ciriaco, Nakamura, M., Roshanineshat, A., Li, Z., Gold, R., Jorstad, S., Cordes, J. M., Cho, I., Ho, Luis C., Brissenden, R., van Bemmel, I., Torne, P., Huang, L., Small, D., Rawlings, M. G., Jung, T., Kettenis, Mark, Bower, G. C., Pen, U. L., Cui, Y., Pu, H. Y., Sohn, B. W., Morán, J. M., and Asada, Keiichi

Abstract

Recent developments in compact object astrophysics, especially the discovery of merging neutron stars by LIGO, the imaging of the black hole in M87 by the Event Horizon Telescope, and high- precision astrometry of the Galactic Center at close to the event horizon scale by the GRAVITY experiment motivate the development of numerical source models that solve the equations of general relativistic magnetohydrodynamics (GRMHD). Here we compare GRMHD solutions for the evolution of a magnetized accretion flow where turbulence is promoted by the magnetorotational instability from a set of nine GRMHD codes: Athena++, BHAC, Cosmos++, ECHO, H-AMR, iharm3D, HARM-Noble, IllinoisGRMHD, and KORAL. Agreement among the codes improves as resolution increases, as measured by a consistently applied, specially developed set of code performance metrics. We conclude that the community of GRMHD codes is mature, capable, and consistent on these test problems. © 2019. The American Astronomical Society. All rights reserved.

Published
2019

30. On magnetic reconnection and particle acceleration in relativistic plasmas : Over magnetische reconnectie en deeltjesversnelling in relativistische plasma's

Author

Ripperda, B, Lapenta, G, and Keppens, R

Subjects
Physics::Plasma Physics, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics
Abstract

The research in this thesis is centered around the study of black holes and stars. The objects of study typically have extremely strong electromagnetic fields governing their macroscopic dynamics. They often expel highly energetic outflows as a distinctive feature. Explosive flares, resulting from the release of magnetic energy in the form of relativistic particles are an important example of such outflows. Both the surroundings of the objects and the outflows consist of a tenuous gas of charged particles, called a plasma. The microscopic dynamics of the plasma are described by the dynamics of these particles. With a combination of several state-of-the-art theoretical and computational methods we study global dynamics of plasma outflows and the interaction with the energetic particles in these plasmas. Magnetohydrodynamics (MHD), couples the plasma to the electromagnetic field. This framework explains many observed plasma-phenomena in the Universe on the global scale. However, it does not capture particle dynamics. Kinetic theory fully captures the nonlinear interaction of charged particles and electromagnetic fields. Applying kinetic theory in astrophysical simulations is typically very demanding and in general cannot capture the global dynamics of the system, contrary to MHD methods. In this work we try to overcome this limitation by applying a combination of MHD methods with test particles. The particles are non-interacting and purely follow the electromagnetic field provided by MHD without acting as a source for the fields. With this method the mechanisms that accelerate particles to extreme energies can be analysed. The most promising acceleration mechanism to explain many astrophysical phenomena is magnetic reconnection. During reconnection, magnetic field lines break due to resistivity, the excess energy in the magnetic field dissipates and is transferred to particles traveling in the plasma. This process is considered to be the generic mechanism behind explosive flares from stars and black holes. In the description of magnetic reconnection both MHD and kinetic theory play an important role on very different time and length scales. It is currently unclear how much of the physics is accurately captured by MHD, and at which scales kinetic physics is necessary to understand reconnection. In this thesis this problem is approached by conducting and comparing simulations in astrophysical conditions with both MHD methods and test particle methods. The MHD method captures the interaction of the global fluid with the fields, whereas the test particle method captures the particle dynamics and acceleration guided by MHD fields. The test particle methods used in this work are presented from first principles and tested for a range of astrophysical problems. Resistivity is a key aspect in the MHD description of reconnection. Energy dissipates from the macroscopic magnetized fluid to the microscopic scales, due to resistivity. On these scales, reconnection typically causes the formation of plasmoids, small 'magnetic islands' confined by a strong magnetic field. These plasmoids, which are populated by high energy particles, can grow to power macroscopic flares. Non-resistive MHD simulations cannot capture plasmoid formation and particle acceleration, that is believed to be responsible for the observed flares. To resolve the mystery of flare formation due to magnetic reconnection, new resistive MHD methods that are able to accurately capture small scales, are developed and employed in this thesis. The difficulty for resistive MHD lies in the fact that dynamics acting on very different time scales have to be captured on a domain that ranges from the typical microscopic resistive scales to the macroscopic astrophysical scales. With a combination of methods the fast time scales are solved separately from the slow time scales, allowing for efficient computation. To cover the extreme range of scales in astrophysics, from the microscopic resistive effects to the global effects on the scale of a compact object, we make use of adaptive mesh refinement. With this method, the underlying grid on which the calculations are done can be refined during the simulation. Based on dynamical properties, it is decided when a finer grid is necessary to accurately resolve smaller scales. Considering that often only a confined area in the domain of a compact object is showing aspects of reconnection and underlying microscopic physics, refining the grid in that specific area can reduce the computing time and increase the accuracy dramatically. Using adaptive mesh refinement, MHD simulations of the emission sites of stars and black holes are extended to low-resistivity regimes that have not been captured accurately before. In extreme astrophysical environments an accurate description of particle dynamics is essential to obtain realistic information of the particle energies that can be linked to observations. A combination of resistive MHD methods with test particles is applied to conduct large-scale simulations of interacting magnetic islands in 2D and interacting flux ropes 3D. The settings are chosen in accordance with typical conditions in stellar coronae, pulsar wind nebulae or magnetospheres of neutron stars or black holes. Reconnection is analysed based on global and local MHD indicators, like a strong resistive electric field, resistive current and the formation of plasmoids. In all analysed cases, localised reconnection regions form and the influence of numerical resolution, resistivity, plasma-β and σ is explored. Test particle simulations provide insight on acceleration mechanisms and trajectories in the reconnection regions and produce energy distributions that can be compared to observations. status: published

Published
2018

40. Stability of two-dimensional forced Navier-Stokes flow on a bounded circular domain

Author

Ripperda, B. and Ripperda, B.

Abstract

This research is concerned with the stability of a two-dimensional, electromagnetically forced, zonal flow on a circular domain. Flows like these are found in nature (e.g. shear flow in the atmosphere, Jovian disk) and experiment (e.g. plasma flow in a Fusion reactor) and a requirement for experiments is often that these types of flows remain stable and axi-symmetric. A numerical method is developed based on a spectral expansion into an infinite system of ordinary differential equations for velocity functions resulting from a Stokes eigenvalue problem. The system is truncated to gain a finite-dimensional system which is useful for computations of both equilibrium flows and strongly disturbed flows. Numerical results are compared to both finite difference method results and analytical results for the equilibrium basic flow. Both linear and nonlinear stability are explored for the Navier-Stokes equations on the circular domain and for the system of ordinary differential equations. Differences in stability and the evolution of perturbations are explained on the basis of discrepancies between infinite-dimensional partial differential equations like the Navier-Stokes equations and a finite-dimensional system of ordinary differential equations resulting from a Galerkin truncation. On the basis of both stability analyses a control system is developed which stabilizes the system of ordinary differential equations to stay in a desired equilibrium. It is argued that this control system is also usable for the control of the Navier-Stokes equations., This research is concerned with the stability of a two-dimensional, electromagnetically forced, zonal flow on a circular domain. Flows like these are found in nature (e.g. shear flow in the atmosphere, Jovian disk) and experiment (e.g. plasma flow in a Fusion reactor) and a requirement for experiments is often that these types of flows remain stable and axi-symmetric. A numerical method is developed based on a spectral expansion into an infinite system of ordinary differential equations for velocity functions resulting from a Stokes eigenvalue problem. The system is truncated to gain a finite-dimensional system which is useful for computations of both equilibrium flows and strongly disturbed flows. Numerical results are compared to both finite difference method results and analytical results for the equilibrium basic flow. Both linear and nonlinear stability are explored for the Navier-Stokes equations on the circular domain and for the system of ordinary differential equations. Differences in stability and the evolution of perturbations are explained on the basis of discrepancies between infinite-dimensional partial differential equations like the Navier-Stokes equations and a finite-dimensional system of ordinary differential equations resulting from a Galerkin truncation. On the basis of both stability analyses a control system is developed which stabilizes the system of ordinary differential equations to stay in a desired equilibrium. It is argued that this control system is also usable for the control of the Navier-Stokes equations.

Published
2013

41. First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

Author

null Event Horizon Telescope Collaboration, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Andrew Chael, Chi-kwan Chan, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Vedant Dhruv, Sheperd S. Doeleman, Sean Dougal, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Charles F. Gammie, Roberto García, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari Haworth, Michael H. Hecht, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Michael D. Johnson, Svetlana Jorstad, Abhishek V. Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Po Kin Leung, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Ru-Sen Lu, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Daniel Michalik, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Müller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Héctor Olivares, Gisela N. Ortiz-León, Tomoaki Oyama, Feryal Özel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Pötzl, Ben Prather, Jorge A. Preciado-López, Dimitrios Psaltis, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Cañizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Paul Yamaguchi, Doosoo Yoon, André Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao, Claudio Agurto, Alexander Allardi, Rodrigo Amestica, Juan Pablo Araneda, Oriel Arriagada, Jennie L. Berghuis, Alessandra Bertarini, Ryan Berthold, Jay Blanchard, Ken Brown, Mauricio Cárdenas, Michael Cantzler, Patricio Caro, Edgar Castillo-Domínguez, Tin Lok Chan, Chih-Cheng Chang, Dominic O. Chang, Shu-Hao Chang, Song-Chu Chang, Chung-Chen Chen, Ryan Chilson, Tim C. Chuter, Miroslaw Ciechanowicz, Edgar Colin-Beltran, Iain M. Coulson, Joseph Crowley, Nathalie Degenaar, Sven Dornbusch, Carlos A. Durán, Wendeline B. Everett, Aaron Faber, Karl Forster, Miriam M. Fuchs, David M. Gale, Gertie Geertsema, Edouard González, Dave Graham, Frédéric Gueth, Nils W. Halverson, Chih-Chiang Han, Kuo-Chang Han, Yutaka Hasegawa, José Luis Hernández-Rebollar, Cristian Herrera, Ruben Herrero-Illana, Stefan Heyminck, Akihiko Hirota, James Hoge, Shelbi R. Hostler Schimpf, Ryan E. Howie, Yau-De Huang, Homin Jiang, Hao Jinchi, David John, Kimihiro Kimura, Thomas Klein, Derek Kubo, John Kuroda, Caleb Kwon, Richard Lacasse, Robert Laing, Erik M. Leitch, Chao-Te Li, Ching-Tang Liu, Kuan-Yu Liu, Lupin C.-C. Lin, Li-Ming Lu, Felipe Mac-Auliffe, Pierre Martin-Cocher, Callie Matulonis, John K. Maute, Hugo Messias, Zheng Meyer-Zhao, Alfredo Montaña, Francisco Montenegro-Montes, William Montgomerie, Marcos Emir Moreno Nolasco, Dirk Muders, Hiroaki Nishioka, Timothy J. Norton, George Nystrom, Hideo Ogawa, Rodrigo Olivares, Peter Oshiro, Juan Pablo Pérez-Beaupuits, Rodrigo Parra, Neil M. Phillips, Michael Poirier, Nicolas Pradel, Richard Qiu, Philippe A. Raffin, Alexandra S. Rahlin, Jorge Ramírez, Sean Ressler, Mark Reynolds, Iván Rodríguez-Montoya, Alejandro F. Saez-Madain, Jorge Santana, Paul Shaw, Leslie E. Shirkey, Kevin M. Silva, William Snow, Don Sousa, T. K. Sridharan, William Stahm, Anthony A. Stark, John Test, Karl Torstensson, Paulina Venegas, Craig Walther, Ta-Shun Wei, Chris White, Gundolf Wieching, Rudy Wijnands, Jan G. A. Wouterloot, Chen-Yu Yu, Wei Yu (于威), Milagros Zeballos, High Energy Astrophys. & Astropart. Phys (API, FNWI), Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Azulay, R., Asada, K., Bach, U., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Baubock, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chan, C. -K., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. 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J., Sanchez, S., Sanchez-Arguelles, D., Sanchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tilanus, R. P. J., Tiede, P., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yamaguchi, P., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., Agurto, C., Allardi, A., Amestica, R., Araneda, J. P., Arriagada, O., Berghuis, J. L., Bertarini, A., Berthold, R., Blanchard, J., Brown, K., Cardenas, M., Cantzler, M., Caro, P., Castillo-Dominguez, E., Chan, T. L., Chang, C. -C., Chang, D. O., Chang, S. -H., Chang, S. -C., Chen, C. -C., Chilson, R., Chuter, T. C., Ciechanowicz, M., Colin-Beltran, E., Coulson, I. M., Crowley, J., Degenaar, N., Dornbusch, S., Duran, C. A., Everett, W. B., Faber, A., Forster, K., Fuchs, M. M., Gale, D. M., Geertsema, G., Gonzalez, E., Graham, D., Gueth, F., Halverson, N. W., Han, C. -C., Han, K. -C., Hasegawa, Y., Hernandez-Rebollar, J. L., Herrera, C., Herrero-Illana, R., Heyminck, S., Hirota, A., Hoge, J., Hostler Schimpf, S. R., Howie, R. E., Huang, Y. -D., Jiang, H., Jinchi, H., John, D., Kimura, K., Klein, T., Kubo, D., Kuroda, J., Kwon, C., Lacasse, R., Laing, R., Leitch, E. M., Li, C. -T., Liu, C. -T., Liu, K. -Y., Lin, L. C. -C., Lu, L. -M., Mac-Auliffe, F., Martin-Cocher, P., Matulonis, C., Maute, J. K., Messias, H., Meyer-Zhao, Z., Montana, A., Montenegro-Montes, F., Montgomerie, W., Nolasco, M. E. M., Muders, D., Nishioka, H., Norton, T. J., Nystrom, G., Ogawa, H., Olivares, R., Oshiro, P., Perez-Beaupuits, J. 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[0000-0002-4892-9586], Kuo, Cheng-Yu [0000-0001-6211-5581], Bella, Noemi La [0000-0002-8116-9427], Lauer, Tod R. [0000-0003-3234-7247], Lee, Daeyoung [0000-0002-3350-5588], Lee, Sang-Sung [0000-0002-6269-594X], Leung, Po Kin [0000-0002-8802-8256], Levis, Aviad [0000-0001-7307-632X], Li, Zhiyuan [0000-0003-0355-6437], Lico, Rocco [0000-0001-7361-2460], Lindahl, Greg [0000-0002-6100-4772], Lindqvist, Michael [0000-0002-3669-0715], Lisakov, Mikhail [0000-0001-6088-3819], Liu, Jun [0000-0002-7615-7499], Liu, Kuo [0000-0002-2953-7376], Liuzzo, Elisabetta [0000-0003-0995-5201], Lo, Wen-Ping [0000-0003-1869-2503], Lobanov, Andrei P. [0000-0003-1622-1484], Loinard, Laurent [0000-0002-5635-3345], Lonsdale, Colin J. [0000-0003-4062-4654], Lu, Ru-Sen [0000-0002-7692-7967], Mao, Jirong [0000-0002-7077-7195], Marchili, Nicola [0000-0002-5523-7588], Markoff, Sera [0000-0001-9564-0876], Marrone, Daniel P. [0000-0002-2367-1080], Marscher, Alan P. 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[0000-0001-6952-2147], Wu, Qingwen [0000-0003-4773-4987], Yamaguchi, Paul [0000-0002-6017-8199], Yoon, Doosoo [0000-0001-8694-8166], Young, André [0000-0003-0000-2682], Young, Ken [0000-0002-3666-4920], Younsi, Ziri [0000-0001-9283-1191], Yuan, Feng [0000-0003-3564-6437], Yuan, Ye-Fei [0000-0002-7330-4756], Zensus, J. Anton [0000-0001-7470-3321], Zhang, Shuo [0000-0002-2967-790X], Zhao, Guang-Yao [0000-0002-4417-1659], Zhao, Shan-Shan [0000-0002-9774-3606], Berghuis, Jennie L. [0000-0003-2287-158X], Blanchard, Jay [0000-0002-2756-395X], Chan, Tin Lok [0000-0001-9197-932X], Coulson, Iain M. [0000-0002-7316-4626], Degenaar, Nathalie [0000-0002-0092-3548], Durán, Carlos A. [0000-0001-7622-3890], Everett, Wendeline B. [0000-0002-5370-6651], Forster, Karl [0000-0001-5800-5531], Halverson, Nils W. [0000-0003-2606-9340], Herrero-Illana, Ruben [0000-0002-7758-8717], Hirota, Akihiko [0000-0002-0465-5421], Howie, Ryan E. [0000-0002-5451-3624], Kwon, Caleb [0000-0001-9006-7345], Laing, Robert [0000-0001-6786-3087], Leitch, Erik M. [0000-0001-8553-9336], Lin, Lupin C.-C. [0000-0003-4083-9567], Maute, John K. [0000-0002-5744-4249], Messias, Hugo [0000-0002-2985-7994], Montenegro-Montes, Francisco [0000-0002-7430-3771], Muders, Dirk [0000-0002-2315-2571], Pérez-Beaupuits, Juan Pablo [0000-0003-3536-2274], Poirier, Michael [0000-0001-6641-0959], Qiu, Richard [0000-0003-3462-0817], Rahlin, Alexandra S. [0000-0003-3953-1776], Ressler, Sean [0000-0003-0220-5723], Reynolds, Mark [0000-0003-1621-9392], Saez-Madain, Alejandro F. [0000-0002-0804-3414], Sousa, Don [0000-0002-2625-2607], Stark, Anthony A. [0000-0002-2718-9996], White, Chris [0000-0001-7448-4253], Wijnands, Rudy [0000-0002-3516-2152], Wouterloot, Jan G. A. [0000-0002-4694-6905], Yu (于威), Wei [0000-0002-5168-6052], Apollo - University of Cambridge Repository, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Science and Technology Facilities Council (UK), Astronomy, Metsähovi Radio Observatory, Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, and Aalto University

Subjects
Black holes, F520, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, F521, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 5109 Space Sciences, Heterodyne interferometry, Galactic center, General Relativity and Quantum Cosmology, Space and Planetary Science, 5101 Astronomical Sciences, Kerr black holes, Rotating black holes, 51 Physical Sciences, Astrophysics::Galaxy Astrophysics, Mathematics
Abstract

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Full list of authors: Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Bach, Uwe; Baczko, Anne-Kathrin; Ball, David; Balokovic, Mislav; Barrett, John; Baubock, Michi; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamante, Sandra; Byun, Do-Young; Carlstrom, John E.; Ceccobello, Chiara; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cheng, Xiaopeng; Cho, Ilje; Christian, Pierre; Conroy, Nicholas S.; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Dhruv, Vedant; Doeleman, Sheperd S.; Dougal, Sean; Dzib, Sergio A.; Eatough, Ralph P.; Emami, Razieh; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Freeman, William T.; Friberg, Per; Fromm, Christian M.; Fuentes, Antonio; Galison, Peter; Gammie, Charles F.; Garcia, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gomez-Ruiz, Arturo, I; Gomez, Jose L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Haworth, Kari; Hecht, Michael H.; Hesper, Ronald; Heumann, Dirk; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Joshi, Abhishek, V; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Lisakov, Mikhail; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin J.; Lu, Ru-Sen; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Marti-Vidal, Ivan; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Muller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Fuentes, Santiago Navarro; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Olivares, Hector; Ortiz-Leon, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Pietu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Potzl, Felix M.; Prather, Ben; Preciado-Lopez, Jorge A.; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Canizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sanchez, Salvador; Sanchez-Arguelles, David; Sanchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schonfeld, Jonathan; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; Turk, Matthew; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Vos, Jesse; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael F.; Wong, George N.; Wu, Qingwen; Yamaguchi, Paul; Yoon, Doosoo; Young, Andre; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Guang-Yao; Zhao, Shan-Shan; Ozel, Feryal; Agurto, Claudio; Allardi, Alexander; Amestica, Rodrigo; Araneda, Juan Pablo; Arriagada, Oriel; Berghuis, Jennie L.; Bertarini, Alessandra; Berthold, Ryan; Blanchard, Jay; Brown, Ken; Cardenas, Mauricio; Cantzler, Michael; Caro, Patricio; Castillo-Dominguez, Edgar; Chan, Tin Lok; Chang, Chih-Cheng; Chang, Dominic O.; Chang, Shu-Hao; Chang, Song-Chu; Chen, Chung-Chen; Chilson, Ryan; Chuter, Tim C.; Ciechanowicz, Miroslaw; Colin-Beltran, Edgar; Coulson, Iain M.; Crowley, Joseph; Degenaar, Nathalie; Dornbusch, Sven; Duran, Carlos A.; Everett, Wendeline B.; Faber, Aaron; Forster, Karl; Fuchs, Miriam M.; Gale, David M.; Geertsema, Gertie; Gonzalez, Edouard; Graham, Dave; Gueth, Frederic; Halverson, Nils W.; Han, Chih-Chiang; Han, Kuo-Chang; Hasegawa, Yutaka; Hernandez-Rebollar, Jose Luis; Herrera, Cristian; Herrero-Illana, Ruben; Heyminck, Stefan; Hirota, Akihiko; Hoge, James; Schimpf, Shelbi R. Hostler; Howie, Ryan E.; Huang, Yau-De; Jiang, Homin; Jinchi, Hao; John, David; Kimura, Kimihiro; Klein, Thomas; Kubo, Derek; Kuroda, John; Kwon, Caleb; Lacasse, Richard; Laing, Robert; Leitch, Erik M.; Li, Chao-Te; Liu, Ching-Tang; Liu, Kuan-Yu; Lin, Lupin C-C; Lu, Li-Ming; Mac-Auliffe, Felipe; Martin-Cocher, Pierre; Matulonis, Callie; Maute, John K.; Messias, Hugo; Meyer-Zhao, Zheng; Montana, Alfredo; Montenegro-Montes, Francisco; Montgomerie, William; Nolasco, Marcos Emir Moreno; Muders, Dirk; Nishioka, Hiroaki; Norton, Timothy J.; Nystrom, George; Ogawa, Hideo; Olivares, Rodrigo; Oshiro, Peter; Perez-Beaupuits, Juan Pablo; Parra, Rodrigo; Phillips, Neil M.; Poirier, Michael; Pradel, Nicolas; Qiu, Richard; Raffin, Philippe A.; Rahlin, Alexandra S.; Ramirez, Jorge; Ressler, Sean; Reynolds, Mark; Rodriguez-Montoya, Ivan; Saez-Madain, Alejandro F.; Santana, Jorge; Shaw, Paul; Shirkey, Leslie E., Jr.; Silva, Kevin M.; Snow, William; Sousa, Don; Sridharan, T. K.; Stahm, William; Stark, Anthony A.; Test, John; Torstensson, Karl; Venegas, Paulina; Walther, Craig; Wei, Ta-Shun; White, Chris; Wieching, Gundolf; Wijnands, Rudy; Wouterloot, Jan G. A.; Yu, Chen-Yu; Yu, Wei; Zeballos, Milagros; Event Horizon Telescope Collaboration., We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A*), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric array of eight telescopes operating at a wavelength of λ = 1.3 mm. The EHT data resolve a compact emission region with intrahour variability. A variety of imaging and modeling analyses all support an image that is dominated by a bright, thick ring with a diameter of 51.8 ± 2.3 μas (68% credible interval). The ring has modest azimuthal brightness asymmetry and a comparatively dim interior. Using a large suite of numerical simulations, we demonstrate that the EHT images of Sgr A* are consistent with the expected appearance of a Kerr black hole with mass ∼4 × 106 M⊙, which is inferred to exist at this location based on previous infrared observations of individual stellar orbits, as well as maser proper-motion studies. Our model comparisons disfavor scenarios where the black hole is viewed at high inclination (i > 50°), as well as nonspinning black holes and those with retrograde accretion disks. Our results provide direct evidence for the presence of a supermassive black hole at the center of the Milky Way, and for the first time we connect the predictions from dynamical measurements of stellar orbits on scales of 103–105 gravitational radii to event-horizon-scale images and variability. Furthermore, a comparison with the EHT results for the supermassive black hole M87* shows consistency with the predictions of general relativity spanning over three orders of magnitude in central mass. © 2022. The Author(s). Published by the American Astronomical Society., The Event Horizon Telescope Collaboration thanks the following organizations and programs: the Academia Sinica; the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigación y Desarrollo (ANID), Chile via NCN19_058 (TITANs) and Fondecyt 1221421, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University and Radboud University; the ALMA North America Development Fund; the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (although the opinions expressed in this work are those of the author(s) and do not necessarily reflect the views of these Foundations); Chandra DD7-18089X and TM6-17006X; the China Scholarship Council; China Postdoctoral Science Foundation fellowship (2020M671266); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM, projects IN112417 and IN112820); the Dutch Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and grant OCENW.KLEIN.113; the Dutch National Supercomputers, Cartesius and Snellius (NWO Grant 2021.013); the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences, and the Korea Astronomy and Space Science Institute; the European Research Council (ERC) Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the European Union Horizon 2020 research and innovation programme under grant agreements RadioNet (No 730562) and M2FINDERS (No 101018682); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant "JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales" (Grant No. 884631); the Institute for Advanced Study; the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; DFG research grant "Jet physics on horizon scales and beyond" (Grant No. FR 4069/2-1); Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, research at the Flatiron Institute is supported by the Simons Foundation; the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant JPMXP1020200109); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Joint Institute for Computational Fundamental Science, Japan; the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJSSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, JP18K13594, 18K03709, JP19K14761, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555; the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2017YFA0402703, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1440254, AST-1555365, AST-1614868, AST-1615796, AST-1715061, AST-1716327, AST-1716536, OISE-1743747, AST-1816420, AST-1935980, AST-2034306); NSF Astronomy and Astrophysics Postdoctoral Fellowship (AST-1903847); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11873028, 11933007, 11991052, 11991053, 12192220, 12192223); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Brain Pool Program: 2019H1D3A1A01102564, Basic Research Support Grant 2019R1F1A1059721, 2021R1A6A3A01086420, 2022R1C1C1005255); Netherlands Research School for Astronomy (NOVA) Virtual Institute of Accretion (VIA) postdoctoral fellowships; Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovación (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the University of Pretoria for financial aid in the provision of the new Cluster Server nodes and SuperMicro (USA) for a SEEDING GRANT approved towards these nodes in 2020; the Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017- 0709); the Spinoza Prize SPI 78-409; the South African Research Chairs Initiative, through the South African Radio Astronomy Observatory (SARAO, grant ID 77948), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI) of South Africa; the Toray Science Foundation; Swedish Research Council (VR); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001); and the YCAA Prize Postdoctoral Fellowship. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key Research and Development Program (No. 2017YFA0402700) of China and Natural Science Foundation of China grant 11873028. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany) and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. This research is part of the Frontera computing project at the Texas Advanced Computing Center through the Frontera Large-Scale Community Partnerships allocation AST20023. Frontera is made possible by National Science Foundation award OAC-1818253. This research was carried out using resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy Office of Science. Additional work used ABACUS2.0, which is part of the eScience center at Southern Denmark University. Simulations were also performed on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).

Published
2022

42. First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass

Author

null Event Horizon Telescope Collaboration, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Andrew Chael, Chi-kwan Chan, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Vedant Dhruv, Sheperd S. Doeleman, Sean Dougal, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Charles F. Gammie, Roberto García, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari Haworth, Michael H. Hecht, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Michael D. Johnson, Svetlana Jorstad, Abhishek V. Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Po Kin Leung, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Ru-Sen Lu, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Daniel Michalik, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Müller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Héctor Olivares, Gisela N. Ortiz-León, Tomoaki Oyama, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Pötzl, Ben Prather, Jorge A. Preciado-López, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Cañizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Paul Yamaguchi, Doosoo Yoon, André Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao, Dominic O. Chang, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Swedish Research Council, Science and Technology Facilities Council (UK), High Energy Astrophys. & Astropart. Phys (API, FNWI), Astronomy, Metsähovi Radio Observatory, Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, Aalto University, Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Baubock, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chan, C. -K., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gomez-Ruiz, A. I., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., Bella, N. L., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lu, R. -S., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Mus, A., Musoke, G., Myserlis, I., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. N., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Palumbo, D. C. M., Paraschos, G. F., Park, J., Parsons, H., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Prather, B., Preciado-Lopez, J. A., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Romero-Canizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sanchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yamaguchi, P., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., and Chang, D. O.

Subjects
F520, Space and Planetary Science, Black holes, Astronomy, F521, Astronomy and Astrophysics, Mathematics, Astrophysics::Galaxy Astrophysics
Abstract

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Full list of authors: Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Bach, Uwe; Baczko, Anne-Kathrin; Ball, David; Balokovic, Mislav; Barrett, John; Baubock, Michi; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamante, Sandra; Byun, Do-Young; Carlstrom, John E.; Ceccobello, Chiara; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cheng, Xiaopeng; Cho, Ilje; Christian, Pierre; Conroy, Nicholas S.; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Dhruv, Vedant; Doeleman, Sheperd S.; Dougal, Sean; Dzib, Sergio A.; Eatough, Ralph P.; Emami, Razieh; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Freeman, William T.; Friberg, Per; Fromm, Christian M.; Fuentes, Antonio; Galison, Peter; Gammie, Charles F.; Garcia, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gomez-Ruiz, Arturo, I; Gomez, Jose L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Haworth, Kari; Hecht, Michael H.; Hesper, Ronald; Heumann, Dirk; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Joshi, Abhishek, V; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Lisakov, Mikhail; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin J.; Lu, Ru-Sen; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Marti-Vidal, Ivan; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Muller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Fuentes, Santiago Navarro; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Olivares, Hector; Ortiz-Leon, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Pietu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Potzl, Felix M.; Prather, Ben; Preciado-Lopez, Jorge A.; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Canizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sanchez, Salvador; Sanchez-Arguelles, David; Sanchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schonfeld, Jonathan; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; Turk, Matthew; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Vos, Jesse; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael F.; Wong, George N.; Wu, Qingwen; Yamaguchi, Paul; Yoon, Doosoo; Young, Andre; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Guang-Yao; Zhao, Shan-Shan; Chang, Dominic O.; Event Horizon Telescope Collaboration., In this paper we quantify the temporal variability and image morphology of the horizon-scale emission from Sgr A*, as observed by the EHT in 2017 April at a wavelength of 1.3 mm. We find that the Sgr A* data exhibit variability that exceeds what can be explained by the uncertainties in the data or by the effects of interstellar scattering. The magnitude of this variability can be a substantial fraction of the correlated flux density, reaching ∼100% on some baselines. Through an exploration of simple geometric source models, we demonstrate that ring-like morphologies provide better fits to the Sgr A* data than do other morphologies with comparable complexity. We develop two strategies for fitting static geometric ring models to the time-variable Sgr A* data; one strategy fits models to short segments of data over which the source is static and averages these independent fits, while the other fits models to the full data set using a parametric model for the structural variability power spectrum around the average source structure. Both geometric modeling and image-domain feature extraction techniques determine the ring diameter to be 51.8 ± 2.3 μas (68% credible intervals), with the ring thickness constrained to have an FWHM between ∼30% and 50% of the ring diameter. To bring the diameter measurements to a common physical scale, we calibrate them using synthetic data generated from GRMHD simulations. This calibration constrains the angular size of the gravitational radius to be ${4.8}_{-0.7}^{+1.4}$ μas, which we combine with an independent distance measurement from maser parallaxes to determine the mass of Sgr A* to be ${4.0}_{-0.6}^{+1.1}\times {10}^{6}$ M⊙. © 2022. The Author(s). Published by the American Astronomical Society., The Event Horizon Telescope Collaboration thanks the following organizations and programs: the Academia Sinica; the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigación y Desarrollo (ANID), Chile via NCN19_058 (TITANs) and Fondecyt 1221421, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University and Radboud University; the ALMA North America Development Fund; the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (although the opinions expressed in this work are those of the author(s) and do not necessarily reflect the views of these Foundations); Chandra DD7-18089X and TM6-17006X; the China Scholarship Council; China Postdoctoral Science Foundation fellowship (2020M671266); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM, projects IN112417 and IN112820); the Dutch Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and grant OCENW.KLEIN.113; the Dutch National Supercomputers, Cartesius and Snellius (NWO Grant 2021.013); the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences, and the Korea Astronomy and Space Science Institute; the European Research Council (ERC) Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the European Union Horizon 2020 research and innovation programme under grant agreements RadioNet (No 730562) and M2FINDERS (No 101018682); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant 'JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales' (Grant No. 884631); the Institute for Advanced Study; the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; DFG research grant "Jet physics on horizon scales and beyond" (Grant No. FR 4069/2-1); Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, research at the Flatiron Institute is supported by the Simons Foundation; the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant JPMXP1020200109); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Joint Institute for Computational Fundamental Science, Japan; the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJSSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, JP18K13594, 18K03709, JP19K14761, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555; the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2017YFA0402703, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1440254, AST-1555365, AST-1614868, AST-1615796, AST-1715061, AST-1716327, AST-1716536, OISE-1743747, AST-1816420, AST-1935980, AST-2034306); NSF Astronomy and Astrophysics Postdoctoral Fellowship (AST-1903847); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11873028, 11933007, 11991052, 11991053, 12192220, 12192223); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Brain Pool Program: 2019H1D3A1A01102564, Basic Research Support Grant 2019R1F1A1059721, 2021R1A6A3A01086420, 2022R1C1C1005255); Netherlands Research School for Astronomy (NOVA) Virtual Institute of Accretion (VIA) postdoctoral fellowships; Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovación (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the University of Pretoria for financial aid in the provision of the new Cluster Server nodes and SuperMicro (USA) for a SEEDING GRANT approved towards these nodes in 2020; the Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017- 0709); the Spinoza Prize SPI 78-409; the South African Research Chairs Initiative, through the South African Radio Astronomy Observatory (SARAO, grant ID 77948), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI) of South Africa; the Toray Science Foundation; Swedish Research Council (VR); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001); and the YCAA Prize Postdoctoral Fellowship. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key Research and Development Program (No. 2017YFA0402700) of China and Natural Science Foundation of China grant 11873028. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany) and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. This research is part of the Frontera computing project at the Texas Advanced Computing Center through the Frontera Large-Scale Community Partnerships allocation AST20023. Frontera is made possible by National Science Foundation award OAC-1818253. This research was carried out using resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy Office of Science. Additional work used ABACUS2.0, which is part of the eScience center at Southern Denmark University. Simulations were also performed on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).

Published
2022

43. First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric

Author

null Event Horizon Telescope Collaboration, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Andrew Chael, Chi-kwan Chan, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Vedant Dhruv, Sheperd S. Doeleman, Sean Dougal, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Charles F. Gammie, Roberto García, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari Haworth, Michael H. Hecht, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Michael D. Johnson, Svetlana Jorstad, Abhishek V. Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Po Kin Leung, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Ru-Sen Lu, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Daniel Michalik, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Müller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Héctor Olivares, Gisela N. Ortiz-León, Tomoaki Oyama, Feryal Özel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Pötzl, Ben Prather, Jorge A. Preciado-López, Dimitrios Psaltis, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Cañizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Paul Yamaguchi, Doosoo Yoon, André Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao, Astronomy, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Swedish Research Council, Science and Technology Facilities Council (UK), High Energy Astrophys. & Astropart. Phys (API, FNWI), Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Baubock, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chan, C. -K., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gomez-Ruiz, A. I., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lu, R. -S., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Mus, A., Musoke, G., Myserlis, I., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. N., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Paraschos, G. F., Park, J., Parsons, H., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Romero-Canizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sanchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yamaguchi, P., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., Metsähovi Radio Observatory, Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, and Aalto University

Subjects
General Relativity and Quantum Cosmology, F520, Space and Planetary Science, Black holes, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, F521, Kerr black holes, Astronomy and Astrophysics, Mathematics
Abstract

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Full list of authors: Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Bach, Uwe; Baczko, Anne-Kathrin; Ball, David; Balokovic, Mislav; Barrett, John; Baubock, Michi; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamante, Sandra; Byun, Do-Young; Carlstrom, John E.; Ceccobello, Chiara; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cheng, Xiaopeng; Cho, Ilje; Christian, Pierre; Conroy, Nicholas S.; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Dhruv, Vedant; Doeleman, Sheperd S.; Dougal, Sean; Dzib, Sergio A.; Eatough, Ralph P.; Emami, Razieh; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Freeman, William T.; Friberg, Per; Fromm, Christian M.; Fuentes, Antonio; Galison, Peter; Gammie, Charles F.; Garcia, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gomez-Ruiz, Arturo, I; Gomez, Jose L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Haworth, Kari; Hecht, Michael H.; Hesper, Ronald; Heumann, Dirk; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Joshi, Abhishek, V; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Lisakov, Mikhail; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin J.; Lu, Ru-Sen; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Marti-Vidal, Ivan; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Muller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Fuentes, Santiago Navarro; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Olivares, Hector; Ortiz-Leon, Gisela N.; Oyama, Tomoaki; Ozel, Feryal; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Pietu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Potzl, Felix M.; Prather, Ben; Preciado-Lopez, Jorge A.; Psaltis, Dimitrios; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Canizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sanchez, Salvador; Sanchez-Arguelles, David; Sanchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schonfeld, Jonathan; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; Turk, Matthew; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Vos, Jesse; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael F.; Wong, George N.; Wu, Qingwen; Yamaguchi, Paul; Yoon, Doosoo; Young, Andre; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Guang-Yao; Zhao, Shan-Shan; Event Horizon Telescope Collaboration., Astrophysical black holes are expected to be described by the Kerr metric. This is the only stationary, vacuum, axisymmetric metric, without electromagnetic charge, that satisfies Einstein's equations and does not have pathologies outside of the event horizon. We present new constraints on potential deviations from the Kerr prediction based on 2017 EHT observations of Sagittarius A* (Sgr A*). We calibrate the relationship between the geometrically defined black hole shadow and the observed size of the ring-like images using a library that includes both Kerr and non-Kerr simulations. We use the exquisite prior constraints on the mass-to-distance ratio for Sgr A* to show that the observed image size is within ∼10% of the Kerr predictions. We use these bounds to constrain metrics that are parametrically different from Kerr, as well as the charges of several known spacetimes. To consider alternatives to the presence of an event horizon, we explore the possibility that Sgr A* is a compact object with a surface that either absorbs and thermally reemits incident radiation or partially reflects it. Using the observed image size and the broadband spectrum of Sgr A*, we conclude that a thermal surface can be ruled out and a fully reflective one is unlikely. We compare our results to the broader landscape of gravitational tests. Together with the bounds found for stellar-mass black holes and the M87 black hole, our observations provide further support that the external spacetimes of all black holes are described by the Kerr metric, independent of their mass. © 2022. The Author(s). Published by the American Astronomical Society., The Event Horizon Telescope Collaboration thanks the following organizations and programs: the Academia Sinica; the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigación y Desarrollo (ANID), Chile via NCN19_058 (TITANs) and Fondecyt 1221421, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University and Radboud University; the ALMA North America Development Fund; the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (although the opinions expressed in this work are those of the author(s) and do not necessarily reflect the views of these Foundations); Chandra DD7-18089X and TM6-17006X; the China Scholarship Council; China Postdoctoral Science Foundation fellowship (2020M671266); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM, projects IN112417 and IN112820); the Dutch Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and grant OCENW.KLEIN.113; the Dutch National Supercomputers, Cartesius and Snellius (NWO Grant 2021.013); the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences, and the Korea Astronomy and Space Science Institute; the European Research Council (ERC) Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the European Union Horizon 2020 research and innovation programme under grant agreements RadioNet (No 730562) and M2FINDERS (No 101018682); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant 'JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales' (Grant No. 884631); the Institute for Advanced Study; the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; DFG research grant "Jet physics on horizon scales and beyond" (Grant No. FR 4069/2-1); Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, research at the Flatiron Institute is supported by the Simons Foundation; the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant JPMXP1020200109); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Joint Institute for Computational Fundamental Science, Japan; the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJSSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, JP18K13594, 18K03709, JP19K14761, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555; the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2017YFA0402703, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1440254, AST-1555365, AST-1614868, AST-1615796, AST-1715061, AST-1716327, AST-1716536, OISE-1743747, AST-1816420, AST-1935980, AST-2034306); NSF Astronomy and Astrophysics Postdoctoral Fellowship (AST-1903847); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11873028, 11933007, 11991052, 11991053, 12192220, 12192223); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Brain Pool Program: 2019H1D3A1A01102564, Basic Research Support Grant 2019R1F1A1059721, 2021R1A6A3A01086420, 2022R1C1C1005255); Netherlands Research School for Astronomy (NOVA) Virtual Institute of Accretion (VIA) postdoctoral fellowships; Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovación (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the University of Pretoria for financial aid in the provision of the new Cluster Server nodes and SuperMicro (USA) for a SEEDING GRANT approved towards these nodes in 2020; the Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709); the Spinoza Prize SPI 78-409; the South African Research Chairs Initiative, through the South African Radio Astronomy Observatory (SARAO, grant ID 77948), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI) of South Africa; the Toray Science Foundation; Swedish Research Council (VR); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001); and the YCAA Prize Postdoctoral Fellowship. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key Research and Development Program (No. 2017YFA0402700) of China and Natural Science Foundation of China grant 11873028. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany) and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. This research is part of the Frontera computing project at the Texas Advanced Computing Center through the Frontera Large-Scale Community Partnerships allocation AST20023. Frontera is made possible by National Science Foundation award OAC-1818253. This research was carried out using resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy Office of Science. Additional work used ABACUS2.0, which is part of the eScience center at Southern Denmark University. Simulations were also performed on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).

Published
2022

44. The Variability of the Black Hole Image in M87 at the Dynamical Timescale

Author

Kaushik Satapathy, Dimitrios Psaltis, Feryal Özel, Lia Medeiros, Sean T. Dougall, Chi-Kwan Chan, Maciek Wielgus, Ben S. Prather, George N. Wong, Charles F. Gammie, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Wilfred Boland, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamente, Do-Young Byun, John E. Carlstrom, Andrew Chael, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Ilje Cho, Pierre Christian, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Sheperd S. Doeleman, Ralph P. Eatough, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Roberto García, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Michael H. Hecht, Ronald Hesper, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jimenez-Rosales, Michael D. Johnson, Svetlana Jorstad, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Tod R. Lauer, Sang-Sung Lee, Aviad Levis, Yan-Rong Li, Zhiyuan Li, Michael Lindqvist, Rocco Lico, Greg Lindahl, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin Lonsdale, Ru-Sen Lu, Nicholas R. MacDonald, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Karl M. Menten, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Müller, Alejandro Mus Mejías, Gibwa Musoke, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Hiroki Okino, Héctor Olivares, Gisela N. Ortiz-León, Tomoaki Oyama, Daniel C. M. Palumbo, Jongho Park, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Pötzl, Jorge A. Preciado-López, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Mel Rose, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Arguelles, Mahito Sasada, Tuomas Savolainen, F. Peter Schloerb, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Kenji Toma, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Kaj Wiik, Qingwen Wu, Doosoo Yoon, André Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Guang-Yao Zhao, Shan-Shan Zhao, Ministerio de Ciencia e Innovación (España), European Commission, National Science Foundation (US), Academy of Finland, Agencia Nacional de Investigación y Desarrollo (Chile), National Natural Science Foundation of China, National Key Research and Development Program (China), National Aeronautics and Space Administration (US), Ministry of Science and Technology (Taiwan), High Energy Astrophys. & Astropart. Phys (API, FNWI), Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, Astronomy, Satapathy, K., Psaltis, D., Ozel, F., Medeiros, L., Dougall, S. T., Chan, C. -K., Wielgus, M., Prather, B. S., Wong, G. N., Gammie, C. F., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamente, S., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gomez-Ruiz, A. I., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., Lauer, T. R., Lee, S. -S., Levis, A., Li, Y. -R., Li, Z., Lindqvist, M., Lico, R., Lindahl, G., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C., Lu, R. -S., Macdonald, N. R., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Menten, K. M., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Mejias, A. M., Musoke, G., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Palumbo, D. C. M., Park, J., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Preciado-Lopez, J. A., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Traianou, E., Trent, T., Trippe, S., Van Bemmel, I., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wiik, K., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhao, G. -Y., and Zhao, S. -S.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Astronomy, SCHEME, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, F500, MASS, Black hole physics, NOISE, ENERGY, Space and Planetary Science, ACCRETION, Astrophysics - High Energy Astrophysical Phenomena, High energy astrophysics, GRMHD SIMULATIONS
Abstract

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.--Full list of authors: Satapathy, Kaushik; Psaltis, Dimitrios; Özel, Feryal; Medeiros, Lia; Dougall, Sean T.; Chan, Chi-Kwan; Wielgus, Maciek; Prather, Ben S.; Wong, George N.; Gammie, Charles F.; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David; Baloković, Mislav; Barrett, John; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Boland, Wilfred; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamente, Sandra; Byun, Do-Young; Carlstrom, John E.; Chael, Andrew; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cho, Ilje; Christian, Pierre; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Doeleman, Sheperd S.; Eatough, Ralph P.; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Fuentes, Antonio; Galison, Peter; García, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gómez-Ruiz, Arturo I.; Gómez, José L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Hecht, Michael H.; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; Lauer, Tod R.; Lee, Sang-Sung; Levis, Aviad; Li, Yan-Rong; Li, Zhiyuan; Lindqvist, Michael; Lico, Rocco; Lindahl, Greg; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin; Lu, Ru-Sen; MacDonald, Nicholas R.; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Menten, Karl M.; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Müller, Cornelia; Mejías, Alejandro Mus; Musoke, Gibwa; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Okino, Hiroki; Olivares, Héctor; Ortiz-León, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Park, Jongho; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Piétu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Pötzl, Felix M.; Preciado-López, Jorge A.; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Rose, Mel; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruszczyk, Chet; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Sasada, Mahito; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Toma, Kenji; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wiik, Kaj; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhao, Guang-Yao; Zhao, Shan-Shan., The black hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center of the M87 galaxy, this timescale (5–61 days) is comparable to the 6 day extent of the 2017 EHT observations. Closure phases along baseline triangles are robust interferometric observables that are sensitive to the expected structural changes of the images but are free of station-based atmospheric and instrumental errors. We explored the day-to-day variability in closure-phase measurements on all six linearly independent nontrivial baseline triangles that can be formed from the 2017 observations. We showed that three triangles exhibit very low day-to-day variability, with a dispersion of ∼3°–5°. The only triangles that exhibit substantially higher variability (∼90°–180°) are the ones with baselines that cross the visibility amplitude minima on the u–v plane, as expected from theoretical modeling. We used two sets of general relativistic magnetohydrodynamic simulations to explore the dependence of the predicted variability on various black hole and accretion-flow parameters. We found that changing the magnetic field configuration, electron temperature model, or black hole spin has a marginal effect on the model consistency with the observed level of variability. On the other hand, the most discriminating image characteristic of models is the fractional width of the bright ring of emission. Models that best reproduce the observed small level of variability are characterized by thin ring-like images with structures dominated by gravitational lensing effects and thus least affected by turbulence in the accreting plasmas. © 2022. The Author(s). Published by the American Astronomical Society., This work was supported, in part, by the NSF PIRE award 1743747 and NASA ATP award 80NSSC20K0521. L.M. acknowledges support from an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award No. AST-1903847. M.W. acknowledges the support of the Black Hole Initiative at Harvard University, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation to Harvard University. All ray tracing calculations for Set A were performed with the El Gato GPU cluster at the University of Arizona that is funded by NSF award 1228509. All analyses for Set B were performed on CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. The EHT Collaboration thanks the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496, and 315721); the Agencia Nacional de Investigación y Desarrollo, Chile via NCN19058 (TITANs) and Fondecyt 3190878; the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA, and the astronomy institutes of the University of Amsterdam, Leiden University, and Radboud University; the black hole Initiative at Harvard University, through a grant (60477) from the John Templeton Foundation; the China Scholarship Council; Consejo Nacional de Ciencia y Tecnología (Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, and 263356); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (projects IN112417 and IN112820); the European Research Council Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the Gordon and Betty Moore Foundation (grant GBMF-3561); the Istituto Nazionale di Fisica Nucleare sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships; research at the Flatiron Institute is supported by the Simons Foundation; the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS; grants QYZDJ-SSW-SLH057, QYZDJSSW-SYS008, and ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max-Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP18K13594, JP18K03656, JP18H03721, 18K03709, 18H01245, and 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS). FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M-001-011, 106-2119- M-001-027, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-110-005, 108-2112-M-001-048, and 109-2124-M-001-005); the National Aeronautics and Space Administration (NASA; Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, and NASA NuSTAR award 80NSSC20K0645); the National Institute of Natural Sciences of Japan; the National Key Research and Development Program of China (grants 2016YFA0400704 and 2016YFA0400702); the National Science Foundation (NSF; grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1555365, AST-1615796, AST-1715061, AST-1716327, AST-1903847, and AST-2034306); the Natural Science Foundation of China (grants 11573051, 11633006, 11650110427, 10625314, 11721303, 11725312, 11933007, 11991052, and 11991053); a fellowship of China Postdoctoral Science Foundation (2020M671266); the Natural Sciences and Engineering Research Council of Canada (NSERC; including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752 and 2015- R1D1A1A01056807; the Korea Research Fellowship Program: NRF-2015H1D3A1066561 and Basic Research Support Grant 2019R1F1A1059721); the Netherlands Organization for Scientific Research VICI award (grant 639.043.513) and Spinoza Prize SPI 78-409; the New Scientific Frontiers with Precision Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Technology of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017–00648) the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science, and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation, and Science); the Spanish Ministerio de Economía y Competitividad (grants PGC2018-098915-B-C21, AYA2016-80889-P, and PID2019-108995GB-C21); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017–0709); the Toray Science Foundation; the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC), for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001); the European Union's Horizon 2020 research and innovation program under grant agreement No. 730562 RadioNet; ALMA North America Development Fund; the Academia Sinica; Chandra DD7-18089X and TM6-17006X; the GenT Program (Generalitat Valenciana) Project CIDEGENT/2018/021. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. The simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, and on the HazelHen cluster at the HLRS in Stuttgart. This research was enabled, in part, by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca), and Compute Canada (http://www.computecanada.ca). We thank the staff at the participating observatories, correlation centers, and institutions for their enthusiastic support. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.01154.V. ALMA is a partnership of the European Southern Observatory (ESO; Europe, representing its member states), NSF, and the National Institutes of Natural Sciences of Japan, together with National Research Council (Canada), MOST (Taiwan), the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), and the Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities, Inc. (AUI)/NRAO, and the National Astronomical Observatory of Japan (NAOJ). The NRAO is a facility of the NSF operated under cooperative agreement by AUI. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the OSO (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, CAS, and the National Key R&D Program (No. 2017YFA0402700) of China. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30 m telescope in Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck Gesellschaft, Germany), and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. The SPT is supported by the NSF through grant PLR-1248097. Partial support is also provided by the NSF Physics Frontier Center grant PHY-1125897 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation, and the Gordon and Betty Moore Foundation grant GBMF 947. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. The EHTC has received generous donations of FPGA chips from Xilinx Inc., under the Xilinx University Program. The EHTC has benefited from technology shared under an open-source license by the Collaboration for Astronomy Signal Processing and Electronics Research. The EHT project is grateful to T4Science and Microsemi for their assistance with hydrogen masers. This research has made use of NASA's Astrophysics Data System. We gratefully acknowledge the support provided by the extended staff of the ALMA, both from the inception of the ALMA Phasing Project through the observational campaigns of 2017 and 2018.

Published
2022

45. A Universal Power-law Prescription for Variability from Synthetic Images of Black Hole Accretion Flows

Author

Boris Georgiev, Dominic W. Pesce, Avery E. Broderick, George N. Wong, Vedant Dhruv, Maciek Wielgus, Charles F. Gammie, Chi-kwan Chan, Koushik Chatterjee, Razieh Emami, Yosuke Mizuno, Roman Gold, Christian M. Fromm, Angelo Ricarte, Doosoo Yoon, Abhishek V. Joshi, Ben Prather, Alejandro Cruz-Osorio, Michael D. Johnson, Oliver Porth, Héctor Olivares, Ziri Younsi, Luciano Rezzolla, Jesse Vos, Richard Qiu, Antonios Nathanail, Ramesh Narayan, Andrew Chael, Richard Anantua, Monika Moscibrodzka, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Sheperd S. Doeleman, Sean Dougal, Sergio A. Dzib, Ralph P. Eatough, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Antonio Fuentes, Peter Galison, Roberto García, Olivier Gentaz, Ciriaco Goddi, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari Haworth, Michael H. Hecht, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Svetlana Jorstad, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Luis Lehner, Po Kin Leung, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Ru-Sen Lu, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Karl M. Menten, Daniel Michalik, Izumi Mizuno, James M. Moran, Kotaro Moriyama, Cornelia Müller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Gopal Narayanan, Iniyan Natarajan, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Gisela N. Ortiz-León, Tomoaki Oyama, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Felix M. Pötzl, Jorge A. Preciado-López, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Cañizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, Qingwen Wu, Paul Yamaguchi, André Young, Ken Young, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, University of Waterloo, Harvard University, Institute for Advanced Studies, University of Illinois at Urbana-Champaign, Max Planck Institute for Radio Astronomy, University of Arizona, Shanghai Jiao Tong University, University of Southern Denmark, University of Amsterdam, Goethe University Frankfurt, Radboud University Nijmegen, Princeton University, CSIC - Institute of Astrophysics of Andalusia, University of Malaya, Academia Sinica - Institute of Astronomy and Astrophysics, Yale University, Massachusetts Institute of Technology, Fermi National Accelerator Laboratory, East Asian Observatory, Anne Lähteenmäki Group, Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, Aalto University, High Energy Astrophys. & Astropart. Phys (API, FNWI), Georgiev, B., Pesce, D. W., Broderick, A. E., Wong, G. N., Dhruv, V., Wielgus, M., Gammie, C. F., Chan, C. -K., Chatterjee, K., Emami, R., Mizuno, Y., Gold, R., Fromm, C. M., Ricarte, A., Yoon, D., Joshi, A. V., Prather, B., Cruz-Osorio, A., Johnson, M. D., Porth, O., Olivares, H., Younsi, Z., Rezzolla, L., Vos, J., Qiu, R., Nathanail, A., Narayan, R., Chael, A., Anantua, R., Moscibrodzka, M., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Baubock, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fuentes, A., Galison, P., Garcia, R., Gentaz, O., Goddi, C., Gomez-Ruiz, A. I., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Lehner, L., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lu, R. -S., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Menten, K. M., Michalik, D., Mizuno, I., Moran, J. M., Moriyama, K., Muller, C., Mus, A., Musoke, G., Myserlis, I., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayanan, G., Natarajan, I., Fuentes, S. N., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Ortiz-Leon, G. N., Oyama, T., Palumbo, D. C. M., Paraschos, G. F., Park, J., Parsons, H., Patel, N., Pen, U. -L., Pietu, V., Plambeck, R., Popstefanija, A., Potzl, F. M., Preciado-Lopez, J. A., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Romero-Canizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sanchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wiik, K., Witzel, G., Wondrak, M. F., Wu, Q., Yamaguchi, P., Young, A., Young, K., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., and Astronomy

Subjects
Accretion, F520, Black holes, Astronomy, F521, Astrophysics::High Energy Astrophysical Phenomena, Stellar accretion, Astronomy and Astrophysics, Galactic center, Magnetohydrodynamics, Space and Planetary Science, Mathematics, Very long baseline interferometry
Abstract

Full list of authors: Georgiev, Boris; Pesce, Dominic W.; Broderick, Avery E.; Wong, George N.; Dhruv, Vedant; Wielgus, Maciek; Gammie, Charles F.; Chan, Chi-kwan; Chatterjee, Koushik ; Emami, Razieh; Mizuno, Yosuke; Gold, Roman; Fromm, Christian M.; Ricarte, Angelo; Yoon, Doosoo; Joshi, Abhishek V.; Prather, Ben; Cruz-Osorio, Alejandro; Johnson, Michael D.; Porth, Oliver; Olivares, Héctor; Younsi, Ziri; Rezzolla, Luciano; Vos, Jesse; Qiu, Richard; Nathanail, Antonios; Narayan, Ramesh; Chael, Andrew; Anantua, Richard; Moscibrodzka, Monika; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Asada, Keiichi; Azulay, Rebecca; Bach, Uwe; Baczko, Anne-Kathrin; Ball, David; Baloković, Mislav; Barrett, John; Bauböck, Michi; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broguiere, Dominique; Bronzwaer, Thomas; Bustamante, Sandra; Byun, Do-Young; Carlstrom, John E.; Ceccobello, Chiara; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cheng, Xiaopeng; Cho, Ilje; Christian, Pierre; Conroy, Nicholas S.; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Doeleman, Sheperd S.; Dougal, Sean; Dzib, Sergio A.; Eatough, Ralph P.; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Freeman, William T.; Friberg, Per; Fuentes, Antonio; Galison, Peter; García, Roberto; Gentaz, Olivier; Goddi, Ciriaco; Gómez-Ruiz, Arturo I.; Gómez, José L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Haworth, Kari; Hecht, Michael H.; Hesper, Ronald; Heumann, Dirk; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jiménez-Rosales, Alejandra; Jorstad, Svetlana; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Lehner, Luis; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Lisakov, Mikhail; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin J.; Lu, Ru-Sen; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Moran, James M.; Moriyama, Kotaro; Müller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayanan, Gopal; Natarajan, Iniyan; Navarro Fuentes, Santiago; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Ortiz-León, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Piétu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Pötzl, Felix M.; Preciado-López, Jorge A.; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Cañizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Argüelles, David; Sánchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schonfeld, Jonathan; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; Turk, Matthew; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael F.; Wu, Qingwen; Yamaguchi, Paul; Young, André; Young, Ken; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Guang-Yao; Zhao, Shan-Shan.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We present a framework for characterizing the spatiotemporal power spectrum of the variability expected from the horizon-scale emission structure around supermassive black holes, and we apply this framework to a library of general relativistic magnetohydrodynamic (GRMHD) simulations and associated general relativistic ray-traced images relevant for Event Horizon Telescope (EHT) observations of Sgr A*. We find that the variability power spectrum is generically a red-noise process in both the temporal and spatial dimensions, with the peak in power occurring on the longest timescales and largest spatial scales. When both the time-averaged source structure and the spatially integrated light-curve variability are removed, the residual power spectrum exhibits a universal broken power-law behavior. On small spatial frequencies, the residual power spectrum rises as the square of the spatial frequency and is proportional to the variance in the centroid of emission. Beyond some peak in variability power, the residual power spectrum falls as that of the time-averaged source structure, which is similar across simulations; this behavior can be naturally explained if the variability arises from a multiplicative random field that has a steeper high-frequency power-law index than that of the time-averaged source structure. We briefly explore the ability of power spectral variability studies to constrain physical parameters relevant for the GRMHD simulations, which can be scaled to provide predictions for black holes in a range of systems in the optically thin regime. We present specific expectations for the behavior of the M87* and Sgr A* accretion flows as observed by the EHT. © 2022. The Author(s). Published by the American Astronomical Society., The Event Horizon Telescope Collaboration thanks the following organizations and programs: National Science Foundation (awards OISE-1743747, AST-1816420, AST-1716536, AST-1440254, AST-1935980); the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (although the opinions expressed in this work are those of the author(s) and do not necessarily reflect the views of these foundations); NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555; the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigación y Desarrollo (ANID), Chile via NCN19_058 (TITANs) and Fondecyt 1221421, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University, and Radboud University; the Institute for Advanced Study; the China Scholarship Council; Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM, projects IN112417 and IN112820); the European Research Council Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant "JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales" (grant No. 884631); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the two Dutch National Supercomputers, Cartesius and Snellius (NWO grant 2021.013); the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; DFG research grant "Jet physics on horizon scales and beyond" (grant No. FR 4069/2-1); Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, with research at the Flatiron Institute supported by the Simons Foundation; the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJ-SSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, JP18K13594, 18K03709, JP19K14761, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2017YFA0402703, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1555365, AST-1614868, AST-1615796, AST-1715061, AST-1716327, AST-2034306); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11873028, 11933007, 11991052, 11991053, 12192220, 12192223); NWO grant No. OCENW.KLEIN.113; a fellowship of China Postdoctoral Science Foundation (2020M671266); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Basic Research Support grant 2019R1F1A1059721, 2022R1C1C1005255); the Dutch Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and Spinoza Prize SPI 78-409; and the YCAA Prize Postdoctoral Fellowship. L.M. gratefully acknowledges support from an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award no. AST-1903847. T.K. is supported by MEXT as "Program for Promoting Researches on the Supercomputer Fugaku" (Toward a unified view of the universe: from large-scale structures to planets, JPMXP1020200109) and JICFuS. R.P.D. and I.N. acknowledge funding by the South African Research Chairs Initiative, through the South African Radio Astronomy Observatory (SARAO, grant ID 77948), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI) of South Africa. We thank the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovación (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the University of Pretoria for financial aid in the provision of the new Cluster Server nodes and SuperMicro (USA) for a SEEDING GRANT approved toward these nodes in 2020; the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709); the Toray Science Foundation; the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the M2FINDERS project, which has received funding by the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement No. 101018682); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (contract 89233218CNA000001); the European Union's Horizon 2020 research and innovation program under grant agreement No. 730562 RadioNet; Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); ALMA North America Development Fund; the Academia Sinica; Chandra DD7-18089X and TM6-17006X; and the GenT Program (Generalitat Valenciana) Project CIDEGENT/2018/021. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. The XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. The XSEDE JetStream resource at PTI and TACC was allocated through AST170028. The simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, and on the HazelHen cluster at the HLRS in Stuttgart. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca), and Compute Canada (http://www.computecanada.ca). C.C. acknowledges support from the Swedish Research Council (VR). We thank the staff at the participating observatories, correlation centers, and institutions for their enthusiastic support. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.01154.V. ALMA is a partnership of the European Southern Observatory (ESO; Europe, representing its member states), NSF, and National Institutes of Natural Sciences of Japan, together with National Research Council (Canada), Ministry of Science and Technology (MOST; Taiwan), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), and Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities, Inc. (AUI)/NRAO, and the National Astronomical Observatory of Japan (NAOJ). The NRAO is a facility of the NSF operated under cooperative agreement by AUI. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract No. DE-AC05-00OR22725. We also thank the Center for Computational Astrophysics, National Astronomical Observatory of Japan. Support for this work was also provided by the NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. H.O. and G.M. were supported by Virtual Institute of Accretion (VIA) postdoctoral fellowships from the Netherlands Research School for Astronomy (NOVA). APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key Research and Development Program (No. 2017YFA0402700) of China and Natural Science Foundation of China grant 11873028. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. Simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. J.O. was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A3A01086420; 2022R1C1C1005255). We thank Martin Shepherd for the addition of extra features in the Difmap software that were used for the CLEAN imaging results presented in this paper. The computing cluster of Shanghai VLBI correlator supported by the Special Fund for Astronomy from the Ministry of Finance in China is acknowledged. This work was supported by the Brain Pool Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (019H1D3A1A01102564). This research is part of the Frontera computing project at the Texas Advanced Computing Center through the Frontera Large-Scale Community Partnerships allocation AST20023. Frontera is made possible by National Science Foundation award OAC-1818253. This research was carried out using resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy Office of Science. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30 m telescope on Pico Veleta, Spain, is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany), and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. Support for this work was provided by NASA through the NASA Hubble Fellowship grant No. HST-HF2-51494.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5–26555. Jongho Park acknowledges financial support through the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences, and the Korea Astronomy and Space Science Institute. The EHTC has received generous donations of FPGA chips from Xilinx Inc., under the Xilinx University Program. The EHTC has benefited from technology shared under open-source license by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER). The EHT project is grateful to T4Science and Microsemi for their assistance with Hydrogen Masers. This research has made use of NASA's Astrophysics Data System. We gratefully acknowledge the support provided by the extended staff of the ALMA, both from the inception of the ALMA Phasing Project through the observational campaigns of 2017 and 2018. We would like to thank A. Deller and W. Brisken for EHT-specific support with the use of DiFX.

Published
2022

46. First Sagittarius A* Event Horizon Telescope results. V. Testing astrophysical models of the Galactic Center black hole

Author

null Event Horizon Telescope Collaboration, Kazunori Akiyama, Antxon Alberdi, Walter Alef, Juan Carlos Algaba, Richard Anantua, Keiichi Asada, Rebecca Azulay, Uwe Bach, Anne-Kathrin Baczko, David Ball, Mislav Baloković, John Barrett, Michi Bauböck, Bradford A. Benson, Dan Bintley, Lindy Blackburn, Raymond Blundell, Katherine L. Bouman, Geoffrey C. Bower, Hope Boyce, Michael Bremer, Christiaan D. Brinkerink, Roger Brissenden, Silke Britzen, Avery E. Broderick, Dominique Broguiere, Thomas Bronzwaer, Sandra Bustamante, Do-Young Byun, John E. Carlstrom, Chiara Ceccobello, Andrew Chael, Chi-kwan Chan, Koushik Chatterjee, Shami Chatterjee, Ming-Tang Chen, Yongjun Chen, Xiaopeng Cheng, Ilje Cho, Pierre Christian, Nicholas S. Conroy, John E. Conway, James M. Cordes, Thomas M. Crawford, Geoffrey B. Crew, Alejandro Cruz-Osorio, Yuzhu Cui, Jordy Davelaar, Mariafelicia De Laurentis, Roger Deane, Jessica Dempsey, Gregory Desvignes, Jason Dexter, Vedant Dhruv, Sheperd S. Doeleman, Sean Dougal, Sergio A. Dzib, Ralph P. Eatough, Razieh Emami, Heino Falcke, Joseph Farah, Vincent L. Fish, Ed Fomalont, H. Alyson Ford, Raquel Fraga-Encinas, William T. Freeman, Per Friberg, Christian M. Fromm, Antonio Fuentes, Peter Galison, Charles F. Gammie, Roberto García, Olivier Gentaz, Boris Georgiev, Ciriaco Goddi, Roman Gold, Arturo I. Gómez-Ruiz, José L. Gómez, Minfeng Gu, Mark Gurwell, Kazuhiro Hada, Daryl Haggard, Kari Haworth, Michael H. Hecht, Ronald Hesper, Dirk Heumann, Luis C. Ho, Paul Ho, Mareki Honma, Chih-Wei L. Huang, Lei Huang, David H. Hughes, Shiro Ikeda, C. M. Violette Impellizzeri, Makoto Inoue, Sara Issaoun, David J. James, Buell T. Jannuzi, Michael Janssen, Britton Jeter, Wu Jiang, Alejandra Jiménez-Rosales, Michael D. Johnson, Svetlana Jorstad, Abhishek V. Joshi, Taehyun Jung, Mansour Karami, Ramesh Karuppusamy, Tomohisa Kawashima, Garrett K. Keating, Mark Kettenis, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kim, Motoki Kino, Jun Yi Koay, Prashant Kocherlakota, Yutaro Kofuji, Patrick M. Koch, Shoko Koyama, Carsten Kramer, Michael Kramer, Thomas P. Krichbaum, Cheng-Yu Kuo, Noemi La Bella, Tod R. Lauer, Daeyoung Lee, Sang-Sung Lee, Po Kin Leung, Aviad Levis, Zhiyuan Li, Rocco Lico, Greg Lindahl, Michael Lindqvist, Mikhail Lisakov, Jun Liu, Kuo Liu, Elisabetta Liuzzo, Wen-Ping Lo, Andrei P. Lobanov, Laurent Loinard, Colin J. Lonsdale, Ru-Sen Lu, Jirong Mao, Nicola Marchili, Sera Markoff, Daniel P. Marrone, Alan P. Marscher, Iván Martí-Vidal, Satoki Matsushita, Lynn D. Matthews, Lia Medeiros, Karl M. Menten, Daniel Michalik, Izumi Mizuno, Yosuke Mizuno, James M. Moran, Kotaro Moriyama, Monika Moscibrodzka, Cornelia Müller, Alejandro Mus, Gibwa Musoke, Ioannis Myserlis, Andrew Nadolski, Hiroshi Nagai, Neil M. Nagar, Masanori Nakamura, Ramesh Narayan, Gopal Narayanan, Iniyan Natarajan, Antonios Nathanail, Santiago Navarro Fuentes, Joey Neilsen, Roberto Neri, Chunchong Ni, Aristeidis Noutsos, Michael A. Nowak, Junghwan Oh, Hiroki Okino, Héctor Olivares, Gisela N. Ortiz-León, Tomoaki Oyama, Feryal Özel, Daniel C. M. Palumbo, Georgios Filippos Paraschos, Jongho Park, Harriet Parsons, Nimesh Patel, Ue-Li Pen, Dominic W. Pesce, Vincent Piétu, Richard Plambeck, Aleksandar PopStefanija, Oliver Porth, Felix M. Pötzl, Ben Prather, Jorge A. Preciado-López, Dimitrios Psaltis, Hung-Yi Pu, Venkatessh Ramakrishnan, Ramprasad Rao, Mark G. Rawlings, Alexander W. Raymond, Luciano Rezzolla, Angelo Ricarte, Bart Ripperda, Freek Roelofs, Alan Rogers, Eduardo Ros, Cristina Romero-Cañizales, Arash Roshanineshat, Helge Rottmann, Alan L. Roy, Ignacio Ruiz, Chet Ruszczyk, Kazi L. J. Rygl, Salvador Sánchez, David Sánchez-Argüelles, Miguel Sánchez-Portal, Mahito Sasada, Kaushik Satapathy, Tuomas Savolainen, F. Peter Schloerb, Jonathan Schonfeld, Karl-Friedrich Schuster, Lijing Shao, Zhiqiang Shen, Des Small, Bong Won Sohn, Jason SooHoo, Kamal Souccar, He Sun, Fumie Tazaki, Alexandra J. Tetarenko, Paul Tiede, Remo P. J. Tilanus, Michael Titus, Pablo Torne, Efthalia Traianou, Tyler Trent, Sascha Trippe, Matthew Turk, Ilse van Bemmel, Huib Jan van Langevelde, Daniel R. van Rossum, Jesse Vos, Jan Wagner, Derek Ward-Thompson, John Wardle, Jonathan Weintroub, Norbert Wex, Robert Wharton, Maciek Wielgus, Kaj Wiik, Gunther Witzel, Michael F. Wondrak, George N. Wong, Qingwen Wu, Paul Yamaguchi, Doosoo Yoon, André Young, Ken Young, Ziri Younsi, Feng Yuan, Ye-Fei Yuan, J. Anton Zensus, Shuo Zhang, Guang-Yao Zhao, Shan-Shan Zhao, Tin Lok Chan, Richard Qiu, Sean Ressler, Chris White, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Swedish Research Council, Science and Technology Facilities Council (UK), Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Baubock, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chan, C. -K., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gomez-Ruiz, A. I., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., Bella, N. L., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lu, R. -S., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Mus, A., Musoke, G., Myserlis, I., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. N., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Paraschos, G. F., Park, J., Parsons, H., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Romero-Canizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sanchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yamaguchi, P., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., Chan, T. L., Qiu, R., Ressler, S., White, C., Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, Aalto University, Akiyama, Kazunori [0000-0002-9475-4254], Alberdi, Antxon [0000-0002-9371-1033], Carlos Algaba, Juan [0000-0001-6993-1696], Anantua, Richard [0000-0003-3457-7660], Asada, Keiichi [0000-0001-6988-8763], Azulay, Rebecca [0000-0002-2200-5393], Bach, Uwe [0000-0002-7722-8412], Baczko, Anne-Kathrin [0000-0003-3090-3975], Baloković, Mislav [0000-0003-0476-6647], Barrett, John [0000-0002-9290-0764], Bauböck, Michi [0000-0002-5518-2812], Benson, Bradford A. [0000-0002-5108-6823], Blackburn, Lindy [0000-0002-9030-642X], Blundell, Raymond [0000-0002-5929-5857], Bouman, Katherine L. [0000-0003-0077-4367], Bower, Geoffrey C. [0000-0003-4056-9982], Boyce, Hope [0000-0002-6530-5783], Brinkerink, Christiaan D. [0000-0002-2322-0749], Brissenden, Roger [0000-0002-2556-0894], Britzen, Silke [0000-0001-9240-6734], Broderick, Avery E. [0000-0002-3351-760X], Broguiere, Dominique [0000-0001-9151-6683], Bronzwaer, Thomas [0000-0003-1151-3971], Bustamante, Sandra [0000-0001-6169-1894], Byun, Do-Young [0000-0003-1157-4109], Carlstrom, John E. [0000-0002-2044-7665], Ceccobello, Chiara [0000-0002-4767-9925], Chael, Andrew [0000-0003-2966-6220], Chan, Chi-kwan [0000-0001-6337-6126], Chatterjee, Koushik [0000-0002-2825-3590], Chatterjee, Shami [0000-0002-2878-1502], Chen, Ming-Tang [0000-0001-6573-3318], Chen, Yongjun [0000-0001-5650-6770], Cheng, Xiaopeng [0000-0003-4407-9868], Cho, Ilje [0000-0001-6083-7521], Christian, Pierre [0000-0001-6820-9941], Conroy, Nicholas S. [0000-0003-2886-2377], Conway, John E. [0000-0003-2448-9181], Cordes, James M. [0000-0002-4049-1882], Crawford, Thomas M. [0000-0001-9000-5013], Crew, Geoffrey B. [0000-0002-2079-3189], Cruz-Osorio, Alejandro [0000-0002-3945-6342], Cui, Yuzhu [0000-0001-6311-4345], Davelaar, Jordy [0000-0002-2685-2434], De Laurentis, Mariafelicia [0000-0002-9945-682X], Deane, Roger [0000-0003-1027-5043], Dempsey, Jessica [0000-0003-1269-9667], Desvignes, Gregory [0000-0003-3922-4055], Dexter, Jason [0000-0003-3903-0373], Dhruv, Vedant [0000-0001-6765-877X], Doeleman, Sheperd S. [0000-0002-9031-0904], Dougal, Sean [0000-0002-3769-1314], Dzib, Sergio A. [0000-0001-6010-6200], Eatough, Ralph P. [0000-0001-6196-4135], Emami, Razieh [0000-0002-2791-5011], Falcke, Heino [0000-0002-2526-6724], Farah, Joseph [0000-0003-4914-5625], Fish, Vincent L. [0000-0002-7128-9345], Fomalont, Ed [0000-0002-9036-2747], Ford, H. Alyson [0000-0002-9797-0972], Fraga-Encinas, Raquel [0000-0002-5222-1361], Friberg, Per [0000-0002-8010-8454], Fromm, Christian M. [0000-0002-1827-1656], Fuentes, Antonio [0000-0002-8773-4933], Galison, Peter [0000-0002-6429-3872], Gammie, Charles F. [0000-0001-7451-8935], García, Roberto [0000-0002-6584-7443], Gentaz, Olivier [0000-0002-0115-4605], Georgiev, Boris [0000-0002-3586-6424], Goddi, Ciriaco [0000-0002-2542-7743], Gold, Roman [0000-0003-2492-1966], Gómez-Ruiz, Arturo I. [0000-0001-9395-1670], Gómez, José L. [0000-0003-4190-7613], Gu, Minfeng [0000-0002-4455-6946], Gurwell, Mark [0000-0003-0685-3621], Hada, Kazuhiro [0000-0001-6906-772X], Haggard, Daryl [0000-0001-6803-2138], Hecht, Michael H. [0000-0002-4114-4583], Hesper, Ronald [0000-0003-1918-6098], Heumann, Dirk [0000-0002-7671-0047], Ho, Luis C. [0000-0001-6947-5846], Ho, Paul [0000-0002-3412-4306], Honma, Mareki [0000-0003-4058-9000], Huang, Chih-Wei L. [0000-0001-5641-3953], Huang, Lei [0000-0002-1923-227X], Ikeda, Shiro [0000-0002-2462-1448], Violette Impellizzeri, C. M. [0000-0002-3443-2472], Inoue, Makoto [0000-0001-5037-3989], Issaoun, Sara [0000-0002-5297-921X], James, David J. [0000-0001-5160-4486], Jannuzi, Buell T. [0000-0002-1578-6582], Janssen, Michael [0000-0001-8685-6544], Jeter, Britton [0000-0003-2847-1712], Jiang, Wu [0000-0001-7369-3539], Jiménez-Rosales, Alejandra [0000-0002-2662-3754], Johnson, Michael D. [0000-0002-4120-3029], Jorstad, Svetlana [0000-0001-6158-1708], Joshi, Abhishek V. [0000-0002-2514-5965], Jung, Taehyun [0000-0001-7003-8643], Karami, Mansour [0000-0001-7387-9333], Karuppusamy, Ramesh [0000-0002-5307-2919], Kawashima, Tomohisa [0000-0001-8527-0496], Keating, Garrett K. [0000-0002-3490-146X], Kettenis, Mark [0000-0002-6156-5617], Kim, Dong-Jin [0000-0002-7038-2118], Kim, Jae-Young [0000-0001-8229-7183], Kim, Jongsoo [0000-0002-1229-0426], Kim, Junhan [0000-0002-4274-9373], Kino, Motoki [0000-0002-2709-7338], Koay, Jun Yi [0000-0002-7029-6658], Kocherlakota, Prashant [0000-0001-7386-7439], Koch, Patrick M. [0000-0003-2777-5861], Koyama, Shoko [0000-0002-3723-3372], Kramer, Carsten [0000-0002-4908-4925], Kramer, Michael [0000-0002-4175-2271], Krichbaum, Thomas P. [0000-0002-4892-9586], Kuo, Cheng-Yu [0000-0001-6211-5581], Bella, Noemi La [0000-0002-8116-9427], Lauer, Tod R. [0000-0003-3234-7247], Lee, Daeyoung [0000-0002-3350-5588], Lee, Sang-Sung [0000-0002-6269-594X], Leung, Po Kin [0000-0002-8802-8256], Levis, Aviad [0000-0001-7307-632X], Li, Zhiyuan [0000-0003-0355-6437], Lico, Rocco [0000-0001-7361-2460], Lindahl, Greg [0000-0002-6100-4772], Lindqvist, Michael [0000-0002-3669-0715], Lisakov, Mikhail [0000-0001-6088-3819], Liu, Jun [0000-0002-7615-7499], Liu, Kuo [0000-0002-2953-7376], Liuzzo, Elisabetta [0000-0003-0995-5201], Lo, Wen-Ping [0000-0003-1869-2503], Lobanov, Andrei P. [0000-0003-1622-1484], Loinard, Laurent [0000-0002-5635-3345], Lonsdale, Colin J. [0000-0003-4062-4654], Lu, Ru-Sen [0000-0002-7692-7967], Mao, Jirong [0000-0002-7077-7195], Marchili, Nicola [0000-0002-5523-7588], Markoff, Sera [0000-0001-9564-0876], Marrone, Daniel P. [0000-0002-2367-1080], Marscher, Alan P. [0000-0001-7396-3332], Martí-Vidal, Iván [0000-0003-3708-9611], Matsushita, Satoki [0000-0002-2127-7880], Matthews, Lynn D. [0000-0002-3728-8082], Medeiros, Lia [0000-0003-2342-6728], Menten, Karl M. [0000-0001-6459-0669], Michalik, Daniel [0000-0002-7618-6556], Mizuno, Izumi [0000-0002-7210-6264], Mizuno, Yosuke [0000-0002-8131-6730], Moran, James M. [0000-0002-3882-4414], Moriyama, Kotaro [0000-0003-1364-3761], Moscibrodzka, Monika [0000-0002-4661-6332], Müller, Cornelia [0000-0002-2739-2994], Mus, Alejandro [0000-0003-0329-6874], Musoke, Gibwa [0000-0003-1984-189X], Myserlis, Ioannis [0000-0003-3025-9497], Nadolski, Andrew [0000-0001-9479-9957], Nagai, Hiroshi [0000-0003-0292-3645], Nagar, Neil M. [0000-0001-6920-662X], Nakamura, Masanori [0000-0001-6081-2420], Narayan, Ramesh [0000-0002-1919-2730], Narayanan, Gopal [0000-0002-4723-6569], Natarajan, Iniyan [0000-0001-8242-4373], Neilsen, Joey [0000-0002-8247-786X], Neri, Roberto [0000-0002-7176-4046], Ni, Chunchong [0000-0003-1361-5699], Noutsos, Aristeidis [0000-0002-4151-3860], Nowak, Michael A. [0000-0001-6923-1315], Oh, Junghwan [0000-0002-4991-9638], Okino, Hiroki [0000-0003-3779-2016], Olivares, Héctor [0000-0001-6833-7580], Ortiz-León, Gisela N. [0000-0002-2863-676X], Oyama, Tomoaki [0000-0003-4046-2923], Özel, Feryal [0000-0003-4413-1523], Palumbo, Daniel C. M. [0000-0002-7179-3816], Filippos Paraschos, Georgios [0000-0001-6757-3098], Park, Jongho [0000-0001-6558-9053], Parsons, Harriet [0000-0002-6327-3423], Patel, Nimesh [0000-0002-6021-9421], Pen, Ue-Li [0000-0003-2155-9578], Pesce, Dominic W. [0000-0002-5278-9221], Plambeck, Richard [0000-0001-6765-9609], Porth, Oliver [0000-0002-4584-2557], Pötzl, Felix M. [0000-0002-6579-8311], Prather, Ben [0000-0002-0393-7734], Preciado-López, Jorge A. [0000-0002-4146-0113], Psaltis, Dimitrios [0000-0003-1035-3240], Pu, Hung-Yi [0000-0001-9270-8812], Ramakrishnan, Venkatessh [0000-0002-9248-086X], Rao, Ramprasad [0000-0002-1407-7944], Rawlings, Mark G. [0000-0002-6529-202X], Raymond, Alexander W. [0000-0002-5779-4767], Rezzolla, Luciano [0000-0002-1330-7103], Ricarte, Angelo [0000-0001-5287-0452], Ripperda, Bart [0000-0002-7301-3908], Roelofs, Freek [0000-0001-5461-3687], Rogers, Alan [0000-0003-1941-7458], Ros, Eduardo [0000-0001-9503-4892], Romero-Cañizales, Cristina [0000-0001-6301-9073], Roshanineshat, Arash [0000-0002-8280-9238], Roy, Alan L. [0000-0002-1931-0135], Ruiz, Ignacio [0000-0002-0965-5463], Ruszczyk, Chet [0000-0001-7278-9707], Rygl, Kazi L. J. [0000-0003-4146-9043], Sánchez, Salvador [0000-0002-8042-5951], Sánchez-Argüelles, David [0000-0002-7344-9920], Sánchez-Portal, Miguel [0000-0003-0981-9664], Sasada, Mahito [0000-0001-5946-9960], Satapathy, Kaushik [0000-0003-0433-3585], Savolainen, Tuomas [0000-0001-6214-1085], Schonfeld, Jonathan [0000-0002-8909-2401], Schuster, Karl-Friedrich [0000-0003-2890-9454], Shao, Lijing [0000-0002-1334-8853], Shen, Zhiqiang [0000-0003-3540-8746], Small, Des [0000-0003-3723-5404], Sohn, Bong Won [0000-0002-4148-8378], SooHoo, Jason [0000-0003-1938-0720], Souccar, Kamal [0000-0001-7915-5272], Sun, He [0000-0003-1526-6787], Tazaki, Fumie [0000-0003-0236-0600], Tetarenko, Alexandra J. [0000-0003-3906-4354], Tiede, Paul [0000-0003-3826-5648], Tilanus, Remo P. J. [0000-0002-6514-553X], Titus, Michael [0000-0001-9001-3275], Torne, Pablo [0000-0001-8700-6058], Traianou, Efthalia [0000-0002-1209-6500], Trippe, Sascha [0000-0003-0465-1559], Turk, Matthew [0000-0002-5294-0198], van Bemmel, Ilse [0000-0001-5473-2950], van Langevelde, Huib Jan [0000-0002-0230-5946], van Rossum, Daniel R. [0000-0001-7772-6131], Vos, Jesse [0000-0003-3349-7394], Wagner, Jan [0000-0003-1105-6109], Ward-Thompson, Derek [0000-0003-1140-2761], Wardle, John [0000-0002-8960-2942], Weintroub, Jonathan [0000-0002-4603-5204], Wex, Norbert [0000-0003-4058-2837], Wharton, Robert [0000-0002-7416-5209], Wielgus, Maciek [0000-0002-8635-4242], Wiik, Kaj [0000-0002-0862-3398], Witzel, Gunther [0000-0003-2618-797X], Wondrak, Michael F. [0000-0002-6894-1072], Wong, George N. [0000-0001-6952-2147], Wu, Qingwen [0000-0003-4773-4987], Yamaguchi, Paul [0000-0002-6017-8199], Yoon, Doosoo [0000-0001-8694-8166], Young, André [0000-0003-0000-2682], Young, Ken [0000-0002-3666-4920], Younsi, Ziri [0000-0001-9283-1191], Yuan, Feng [0000-0003-3564-6437], Yuan, Ye-Fei [0000-0002-7330-4756], Zensus, J. Anton [0000-0001-7470-3321], Zhang, Shuo [0000-0002-2967-790X], Zhao, Guang-Yao [0000-0002-4417-1659], Zhao, Shan-Shan [0000-0002-9774-3606], Chan, Tin Lok [0000-0001-9197-932X], Qiu, Richard [0000-0003-3462-0817], Ressler, Sean [0000-0003-0220-5723], White, Chris [0000-0001-7448-4253], Apollo - University of Cambridge Repository, High Energy Astrophys. & Astropart. Phys (API, FNWI), and Astronomy

Subjects
F520, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, F521, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Black hole physics, Galactic center, 5101 Astronomical Sciences, Space and Planetary Science, 51 Physical Sciences, High-Energy Phenomena and Fundamental Physics, Astrophysics::Galaxy Astrophysics, Mathematics
Abstract

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Full list of authors: Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Bach, Uwe; Baczko, Anne-Kathrin; Ball, David; Balokovic, Mislav; Barrett, John; Baubock, Michi; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamante, Sandra; Byun, Do-Young; Carlstrom, John E.; Ceccobello, Chiara; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cheng, Xiaopeng; Cho, Ilje; Christian, Pierre; Conroy, Nicholas S.; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Dhruv, Vedant; Doeleman, Sheperd S.; Dougal, Sean; Dzib, Sergio A.; Eatough, Ralph P.; Emami, Razieh; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Freeman, William T.; Friberg, Per; Fromm, Christian M.; Fuentes, Antonio; Galison, Peter; Gammie, Charles F.; Garcia, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gold, Roman; Gomez-Ruiz, Arturo, I; Gomez, Jose L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Haworth, Kari; Hecht, Michael H.; Hesper, Ronald; Heumann, Dirk; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Impellizzeri, C. M. Violette; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Joshi, Abhishek, V; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Kocherlakota, Prashant; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; La Bella, Noemi; Lauer, Tod R.; Lee, Daeyoung; Lee, Sang-Sung; Leung, Po Kin; Levis, Aviad; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Lisakov, Mikhail; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin J.; Lu, Ru-Sen; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Marti-Vidal, Ivan; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Michalik, Daniel; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Mueller, Cornelia; Mus, Alejandro; Musoke, Gibwa; Myserlis, Ioannis; Nadolski, Andrew; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Fuentes, Santiago Navarro; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Oh, Junghwan; Okino, Hiroki; Olivares, Hector; Ortiz-Leon, Gisela N.; Oyama, Tomoaki; Ozel, Feryal; Palumbo, Daniel C. M.; Paraschos, Georgios Filippos; Park, Jongho; Parsons, Harriet; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Pietu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Potzl, Felix M.; Ben Prather; Preciado-Lopez, Jorge A.; Psaltis, Dimitrios; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Romero-Canizales, Cristina; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruiz, Ignacio; Ruszczyk, Chet; Rygl, Kazi L. J.; Sanchez, Salvador; Sanchez-Arguelles, David; Sanchez-Portal, Miguel; Sasada, Mahito; Satapathy, Kaushik; Savolainen, Tuomas; Schloerb, F. Peter; Schonfeld, Jonathan; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Des Small; Sohn, Bong Won; SooHoo, Jason; Souccar, Kamal; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; Turk, Matthew; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Vos, Jesse; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wiik, Kaj; Witzel, Gunther; Wondrak, Michael F.; Wong, George N.; Wu, Qingwen; Yamaguchi, Paul; Yoon, Doosoo; Young, Andre; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhang, Shuo; Zhao, Guang-Yao; Zhao, Shan-Shan; Chan, Tin Lok; Qiu, Richard; Ressler, Sean; White, Chris; Event Horizon Telescope Collaboration., In this paper we provide a first physical interpretation for the Event Horizon Telescope's (EHT) 2017 observations of Sgr A*. Our main approach is to compare resolved EHT data at 230 GHz and unresolved non-EHT observations from radio to X-ray wavelengths to predictions from a library of models based on time-dependent general relativistic magnetohydrodynamics simulations, including aligned, tilted, and stellar-wind-fed simulations; radiative transfer is performed assuming both thermal and nonthermal electron distribution functions. We test the models against 11 constraints drawn from EHT 230 GHz data and observations at 86 GHz, 2.2 μm, and in the X-ray. All models fail at least one constraint. Light-curve variability provides a particularly severe constraint, failing nearly all strongly magnetized (magnetically arrested disk (MAD)) models and a large fraction of weakly magnetized models. A number of models fail only the variability constraints. We identify a promising cluster of these models, which are MAD and have inclination i ≤ 30°. They have accretion rate (5.2–9.5) × 10−9 M⊙ yr−1, bolometric luminosity (6.8–9.2) × 1035 erg s−1, and outflow power (1.3–4.8) × 1038 erg s−1. We also find that all models with i ≥ 70° fail at least two constraints, as do all models with equal ion and electron temperature; exploratory, nonthermal model sets tend to have higher 2.2 μm flux density; and the population of cold electrons is limited by X-ray constraints due to the risk of bremsstrahlung overproduction. Finally, we discuss physical and numerical limitations of the models, highlighting the possible importance of kinetic effects and duration of the simulations. © 2022. The Author(s). Published by the American Astronomical Society., The Event Horizon Telescope Collaboration thanks the following organizations and programs: the Academia Sinica; the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigación y Desarrollo (ANID), Chile via NCN19_058 (TITANs) and Fondecyt 1221421, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University and Radboud University; the ALMA North America Development Fund; the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation (although the opinions expressed in this work are those of the author(s) and do not necessarily reflect the views of these Foundations); Chandra DD7-18089X and TM6-17006X; the China Scholarship Council; China Postdoctoral Science Foundation fellowship (2020M671266); Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Dirección General de Asuntos del Personal Académico-Universidad Nacional Autónoma de México (DGAPA-UNAM, projects IN112417 and IN112820); the Dutch Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and grant OCENW.KLEIN.113; the Dutch National Supercomputers, Cartesius and Snellius (NWO Grant 2021.013); the EACOA Fellowship awarded by the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, Center for Astronomical Mega-Science, Chinese Academy of Sciences, and the Korea Astronomy and Space Science Institute; the European Research Council (ERC) Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the European Union Horizon 2020 research and innovation programme under grant agreements RadioNet (No 730562) and M2FINDERS (No 101018682); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant 'JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales' (Grant No. 884631); the Institute for Advanced Study; the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; DFG research grant "Jet physics on horizon scales and beyond" (Grant No. FR 4069/2-1); Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, research at the Flatiron Institute is supported by the Simons Foundation; the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant JPMXP1020200109); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Joint Institute for Computational Fundamental Science, Japan; the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJSSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, JP18K13594, 18K03709, JP19K14761, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555; the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2017YFA0402703, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1440254, AST-1555365, AST-1614868, AST-1615796, AST-1715061, AST-1716327, AST-1716536, OISE-1743747, AST-1816420, AST-1935980, AST-2034306); NSF Astronomy and Astrophysics Postdoctoral Fellowship (AST-1903847); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11873028, 11933007, 11991052, 11991053, 12192220, 12192223); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Brain Pool Program: 2019H1D3A1A01102564, Basic Research Support Grant 2019R1F1A1059721, 2021R1A6A3A01086420, 2022R1C1C1005255); Netherlands Research School for Astronomy (NOVA) Virtual Institute of Accretion (VIA) postdoctoral fellowships; Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovación (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the University of Pretoria for financial aid in the provision of the new Cluster Server nodes and SuperMicro (USA) for a SEEDING GRANT approved towards these nodes in 2020; the Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía (SEV-2017- 0709); the Spinoza Prize SPI 78-409; the South African Research Chairs Initiative, through the South African Radio Astronomy Observatory (SARAO, grant ID 77948), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI) of South Africa; the Toray Science Foundation; Swedish Research Council (VR); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001); and the YCAA Prize Postdoctoral Fellowship. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key Research and Development Program (No. 2017YFA0402700) of China and Natural Science Foundation of China grant 11873028. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrófisica, Óptica, y Electrónica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck-Gesellschaft, Germany) and IGN (Instituto Geográfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. This research is part of the Frontera computing project at the Texas Advanced Computing Center through the Frontera Large-Scale Community Partnerships allocation AST20023. Frontera is made possible by National Science Foundation award OAC-1818253. This research was carried out using resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy Office of Science. Additional work used ABACUS2.0, which is part of the eScience center at Southern Denmark University. Simulations were also performed on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).

Published
2022

47. Selective Dynamical Imaging of Interferometric Data

Author

The event horizon telescope collaboration, Pesce, Dominic W., Broderick, Avery E, Wong, George N, Dhruv, Vedant, Wielgus, Maciek, Gammie, Charles F, Chan, Chi-Kwan, Chatterjee, Koushik, Emami, Razieh, Mizuno, Yosuke, Gold, Roman, Fromm, Christian M., Ricarte, Angelo, Yoon, Doosoo, Joshi, Abhishek V, Prather, Ben, Cruz-Osorio, Alejandro, Johnson, Michael D, Port, Oliver, Olivares, Hector, Younsi, Ziri, Rezzolla, Luciano, Vos, Jesse, Wiu, Richard, Nathanail, Antonios, Narayan, Ramesh, Chael, Andrew, Anantua, Richard, Moscibrodzka, Monika, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Asada, Keiichi, Azulay, Rebecca, Li, Yan-Rong, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Boland, Wilfred, Benson, Bradford A, Bintley, Dan, Blackburn, Lindy, Blundell, Raymond, Bouman, Katherine L, Bower, Geoffery C, Boyce, Hope, Bremer, Michael, Brinkerink, Christiaan D, Brissenden, Roger, Brtizen, Silke, Broguiere, Domonique, Bronzwaer, Thomas, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E, MacDonald, Nicholas R, Chatterjee, Shami, Chen, Ming-Tang, Chen, Yongjun, Cheng, Xiaopeng, Cho, Ilje, Christian, Pierre, Feryal, Zel, Conway, John E, Cordes, James M, Crawford, Thomas M, Crew, Geoffrey B, Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelcia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Psaltis, Dimitrios, Doeleman, Sheperd S, Rose, Mel, Toma, Kenji, Eatough, Ralph P, Falcke, Heino, Farah, Joseph, Fish, Vincent L, Fomalont, Ed, Ford, H. Alyson, Fraga-Encinas, Raquel, Moriyama, Kotaro, Friberg, Per, Fuentes, Antonio, Galison, Peter, Garcia, Roberto, Gentaz, Olivier, Goddi, Ciriaco, Gómez-Ruiz, Arturo L, Gómez, José L, Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Hecht, Michael H, Hesper, Ronald, Ho, Luis C, Ho, Paul, Honma, Mareki, Huang, Chih-Wei L, Huang, Lei, Hughes, David H, Ikeda, Shiro, Inoue, Makoto, Issaoun, Sara, James, David J, Jannuzi, Buell T, Janssen, Michael, Jeter, Britton, Jiang, Wu, Jiménez-Rosales, Alejandra, Jorstad, Svetlana, Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K, Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Koay, Jun Yi, Kofuji, Yutaro, Koch, Patrick M, Koyama, Shoko, Kramer, Carsten, Kramer, Michael, Krichbaum, Thomas P, Kuo, Cheng-Yu, Lauer, Tod R, Lee, Sang-Sung, Levis, Aviad, Li, Zhiyuan, Lico, Rocco, Lindahl, Greg, Lindqvist, Michael, Lisakov, Mikhail, Liu, Jun, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P, Loinard, Laurent, Lonsdale, Colin J, Lu, Ru-Sen, Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P, Marscher, Alan P, Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D, Menten, Karl M, Medeiros, Lia, Mizuno, Izumi, Moran, James M, Muller, Cornelia, Mus Mejas, Alejandro, Musoke, Gibwa, Nagai, Hiroshi, Nagar, Neil M, Nakamura, Masanori, Narayanan, Gopal, Natarajan, Iniyan, Fuentes, Santiago Navarro, Neilsen, Joey, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A, Okino, Hiroki, Ortiz-Leon, Gisela N, Oyama, Tomoaki, Palumbo, Daniel C M, Porth, Oliver, Park, Jongho, Patel, Nimesh, Pen, Ue-Li, Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Pötzl, Felix M, Preciado-Lopez, Jorge A, Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G, Raymond, Alexander W, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, Ros, Eduardo, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L, Ruszczyk, Chet, Rygl, Kazi L J, Sanchez, Salvador, Sánchez-Argüelles, David, Sasada, Mahito, Savolainen, Tuomas, Schloerb, F. Peter, Schuster, Karl-Friedrich, Shao, Lijing, Shen, Zhiqiang, Small, Des, Sohn, Bong Won, SooHoo, Jason, Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J, Tiede, Paul, Tilanus, Remo P J, Titus, Michael, Torne, Pablo, Traianou, Efthalia, Trent, Tyler, Trippe, Sascha, Bemmel, Isle van, van Langevelde, Huib Jan, van Rossum, Daniel R, Wagner, Jan, Ward-Thompson, Derek, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wiik, Kaj, Wu, Qingwen, Young, Andre, Young, Ken, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Yao, Zhao, Guang-Yao, Zhao, Shan-Shan, Farah, J., Galison, P., Akiyama, K., Bouman, K. L., Bower, G. C., Chael, A., Fuentes, A., Gomez, J. L., Honma, M., Johnson, M. D., Kofuji, Y., Marrone, D. P., Moriyama, K., Narayan, R., Pesce, D. W., Tiede, P., Wielgus, M., Zhao, G. -Y., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Baczko, A. -K., Ball, D., Balokovic, M., Barrett, J., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Boland, W., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamente, S., Byun, D. -Y., Carlstrom, J. E., Chan, C. -K., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Doeleman, S. S., Eatough, R. P., Falcke, H., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Gammie, C. F., Garc'A, R., Gentaz, O., Goddi, C., Gold, R., Gomez-Ruiz, A. I., Gu, M., Gurwell, M., Hada, K., Haggard, D., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., Lauer, T. R., Lee, S. -S., Levis, A., Li, Y. -R., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C., Lu, R. -S., Macdonald, N. R., Mao, J., Marchili, N., Markoff, S., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, I., Mizuno, Y., Moran, J. M., Moscibrodzka, M., Muller, C., Mejas, A. M., Musoke, G., Nagai, H., Nagar, N. M., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Park, J., Patel, N., Pen, U. -L., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Sun, H., Tazaki, F., Tetarenko, A. J., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Traianou, E., Trent, T., Trippe, S., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wiik, K., Wong, G. N., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhao, S. -S., Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, National Science Foundation (US), Gordon and Betty Moore Foundation, Las Cumbres Observatory Global Telescope Network, Harvard University, Academia Sinica - Institute of Astronomy and Astrophysics, Princeton University, CSIC - Institute of Astrophysics of Andalusia, National Astronomical Observatory of Japan, University of Arizona, Massachusetts Institute of Technology, University of Waterloo, University of Malaya, Universidad de Valencia, Fermi National Accelerator Laboratory, East Asian Observatory, Nederlandse Onderzoekschool voor Astronomie, McGill University, Institut de Radio Astronomie Millimétrique, Radboud University Nijmegen, University of Massachusetts, Korea Astronomy and Space Science Institute, University of Chicago, University of Amsterdam, Universidad de Concepción, Department of Electronics and Nanoengineering, Science Support Office, Aalto-yliopisto, Aalto University, High Energy Astrophys. & Astropart. Phys (API, FNWI), Kapteyn Astronomical Institute, and Astronomy

Subjects
Interferometry, Space and Planetary Science, F520, F521, Astrophysical black holes, Astronomy, Astronomy and Astrophysics, Very long baseline interferometry, Aperture synthesis
Abstract

Full list of authors: Farah, Joseph; Galison, Peter; Akiyama, Kazunori; Bouman, Katherine L.; Bower, Geoffrey C.; Chael, Andrew; Fuentes, Antonio; Gómez, José L.; Honma, Mareki; Johnson, Michael D.; Kofuji, Yutaro; Marrone, Daniel P.; Moriyama, Kotaro; Narayan, Ramesh; Pesce, Dominic W.; Tiede, Paul; Wielgus, Maciek; Zhao, Guang-Yao; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David; Baloković, Mislav; Barrett, John; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Boland, Wilfred; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Bustamente, Sandra; Byun, Do-Young; Carlstrom, John E.; Chan, Chi-kwan; Chatterjee, Koushik; Chatterjee, Shami; Chen, Ming-Tang; Chen, Yongjun; Cho, Ilje; Christian, Pierre; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Doeleman, Sheperd S.; Eatough, Ralph P.; Falcke, Heino; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Gammie, Charles F.; Garc'a, Roberto; Gentaz, Olivier; Goddi, Ciriaco; Gold, Roman; Gómez-Ruiz, Arturo I.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Haggard, Daryl; Hecht, Michael H.; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jimenez-Rosales, Alejandra; Jorstad, Svetlana; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Dong-Jin; Kim, Jae-Young; Kim, Jongsoo; Kim, Junhan; Kino, Motoki; Koay, Jun Yi; Koch, Patrick M.; Koyama, Shoko; Kramer, Carsten; Kramer, Michael; Krichbaum, Thomas P.; Kuo, Cheng-Yu; Lauer, Tod R.; Lee, Sang-Sung; Levis, Aviad; Li, Yan-Rong; Li, Zhiyuan; Lico, Rocco; Lindahl, Greg; Lindqvist, Michael; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin; Lu, Ru-Sen; MacDonald, Nicholas R.; Mao, Jirong; Marchili, Nicola; Markoff, Sera; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moscibrodzka, Monika; Müller, Cornelia; Mejas, Alejandro Mus; Musoke, Gibwa; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Neilsen, Joey; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Nowak, Michael A.; Okino, Hiroki; Olivares, Héctor; Ortiz-León, Gisela N.; Oyama, Tomoaki; zel, Feryal; Palumbo, Daniel C. M.; Park, Jongho; Patel, Nimesh; Pen, Ue-Li; Piétu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Pötzl, Felix M.; Prather, Ben; Preciado-López, Jorge A.; Psaltis, Dimitrios; Pu, Hung-Yi; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Rose, Mel; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruszczyk, Chet; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Sasada, Mahito; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tilanus, Remo P. J.; Titus, Michael; Toma, Kenji; Torne, Pablo; Traianou, Efthalia; Trent, Tyler; Trippe, Sascha; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wiik, Kaj; Wong, George N.; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhao, Shan-Shan; Event Horizon Telescope Collaboration.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT's (u, v)-coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v)-coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A* data set. © 2022. The Author(s). Published by the American Astronomical Society., We thank the National Science Foundation (awards OISE-1743747, AST-1816420, AST-1716536, AST-1440254, AST-1935980) and the Gordon and Betty Moore Foundation (GBMF-5278) for financial support of this work. This work was supported in part by the Black Hole Initiative, which is funded by grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation to Harvard University. Support for this work was also provided by the NASA Hubble Fellowship grant HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. The Event Horizon Telescope Collaboration thanks the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496, 315721); the Agencia Nacional de Investigacin y Desarrollo (ANID), Chile via NCN19058 (TITANs) and Fondecyt 3190878, the Alexander von Humboldt Stiftung; an Alfred P. Sloan Research Fellowship; Allegro, the European ALMA Regional Centre node in the Netherlands, the NL astronomy research network NOVA and the astronomy institutes of the University of Amsterdam, Leiden University, and Radboud University; the Black Hole Initiative at Harvard University, through a grant (60477) from the John Templeton Foundation; the China Scholarship Council; Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico, projects U0004-246083, U0004-259839, F0003-272050, M0037-279006, F0003-281692, 104497, 275201, 263356); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Direccin General de Asuntos del Personal Acadmico-Universidad Nacional Autnoma de Mxico (DGAPA-UNAM, projects IN112417 and IN112820); the European Research Council Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); MICINN Research Project PID2019-108995GB-C22; the European Research Council for advanced grant "JETSET: Launching, propagation and emission of relativistic jets from binary mergers and across mass scales" (grant No. 884631); the Gordon and Betty Moore Foundation (grant GBMF-3561); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the two Dutch National Supercomputers, Cartesius and Snellius (NWO grant 2021.013); the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; Joint Princeton/Flatiron and Joint Columbia/Flatiron Postdoctoral Fellowships, with research at the Flatiron Institute being supported by the Simons Foundation; the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJ-SSW-SYS008, ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP21H01137, JP18H03721, 18K03709, 18H01245, 25120007); the Malaysian Fundamental Research Grant Scheme (FRGS) FRGS/1/2019/STG02/UM/02/6; the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (103-2119-M-001-010-MY2, 105-2112-M-001-025-MY3, 105-2119-M-001-042, 106-2112-M-001-011, 106-2119-M-001-013, 106-2119-M-001-027, 106-2923-M-001-005, 107-2119-M-001-017, 107-2119-M-001-020, 107-2119-M-001-041, 107-2119-M-110-005, 107-2923-M-001-009, 108-2112-M-001-048, 108-2112-M-001-051, 108-2923-M-001-002, 109-2112-M-001-025, 109-2124-M-001-005, 109-2923-M-001-001, 110-2112-M-003-007-MY2, 110-2112-M-001-033, 110-2124-M-001-007, and 110-2923-M-001-001); the Ministry of Education (MoE) of Taiwan Yushan Young Scholar Program; the Physics Division, National Center for Theoretical Sciences of Taiwan; the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC20K1567, NASA Astrophysics Theory Program grant 80NSSC20K0527, NASA NuSTAR award 80NSSC20K0645); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1555365, AST-1615796, AST-1715061, AST-1716327, AST-1903847, AST-2034306); the Natural Science Foundation of China (grants 11650110427, 10625314, 11721303, 11725312, 11933007, 11991052, 11991053); NWO grant No. OCENW.KLEIN.113; a fellowship of China Postdoctoral Science Foundation (2020M671266); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, 2015-R1D1A1A01056807; the Korea Research Fellowship Program: NRF-2015H1D3A1066561, Basic Research Support Grant 2019R1F1A1059721); the Netherlands Organization for Scientific Research (NWO) VICI award (grant 639.043.513) and Spinoza Prize SPI 78-409; the New Scientific Frontiers with Precision Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648); the Perimeter Institute for Theoretical Physics (research at the Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Spanish Ministerio de Ciencia e Innovacin (grants PGC2018-098915-B-C21, AYA2016-80889-P, PID2019-108995GB-C21, PID2020-117404GB-C21); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofsica de Andaluca (SEV-2017-0709); the Toray Science Foundation; the Consejera de Economa, Conocimiento, Empresas y Universidad of the Junta de Andaluca (grant P18-FR-1769), the Consejo Superior de Investigaciones Cientficas (grant 2019AEP112); the M2FINDERS project, which has received funding by the European Research Council (ERC) under the European Unions Horizon 2020 Research and Innovation Programme (grant agreement No. 101018682); the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (contract 89233218CNA000001); the European Unions Horizon 2020 research and innovation program under grant agreement No. 730562 RadioNet; Shanghai Pilot Program for Basic Research, Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2021-013); ALMA North America Development Fund; the Academia Sinica; Chandra DD7-18089X and TM6-17006X; and the GenT Program (Generalitat Valenciana) Project CIDEGENT/2018/021. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. The XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. The XSEDE JetStream resource at PTI and TACC was allocated through AST170028. The simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, and on the HazelHen cluster at the HLRS in Stuttgart. This research was enabled in part by support provided by Compute Ontario (http://computeontario.ca), Calcul Quebec (http://www.calculquebec.ca), and Compute Canada (http://www.computecanada.ca). C.C. acknowledges support from the Swedish Research Council (VR). We thank the staff at the participating observatories, correlation centers, and institutions for their enthusiastic support. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.01154.V. ALMA is a partnership of the European Southern Observatory (ESO; Europe, representing its member states), NSF, and National Institutes of Natural Sciences of Japan, together with National Research Council (Canada), Ministry of Science and Technology (MOST; Taiwan), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), and Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities, Inc. (AUI)/NRAO, and the National Astronomical Observatory of Japan (NAOJ). The NRAO is a facility of the NSF operated under cooperative agreement by AUI. Hector Olivares and Gibwa Musoke were supported by Virtual Institute of Accretion (VIA) postdoctoral fellowships from the Netherlands Research School for Astronomy (NOVA). APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key R&D Program (No. 2017YFA0402700) of China. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. Simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, on the HazelHen cluster at the HLRS in Stuttgart, and on the Pi2.0 and Siyuan Mark-I at Shanghai Jiao Tong University. The computer resources of the Finnish IT Center for Science (CSC) and the Finnish Computing Competence Infrastructure (FCCI) project are acknowledged. Junghwan Oh was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A3A01086420). We thank Martin Shepherd for the addition of extra features in the Difmap software that were used for the CLEAN imaging results presented in this paper. The computing cluster of Shanghai VLBI correlator supported by the Special Fund for Astronomy from the Ministry of Finance in China is acknowledged. The LMT is a project operated by the Instituto Nacional de Astrofisica, Optica, y Electronica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30 m telescope on Pico Veleta, Spain, is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-Planck- Gesellschaft, Germany), and IGN (Instituto Geogrfico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. Support for SPT participation in the EHT is provided by the National Science Foundation through award OPP-1852617 to the University of Chicago. Partial support is also provided by the Kavli Institute of Cosmological Physics at the University of Chicago. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. Support for this work was provided by NASA through the NASA Hubble Fellowship grant No. HST-HF2-51494.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5–26555. The EHTC has received generous donations of FPGA chips from Xilinx Inc., under the Xilinx University Program. The EHTC has benefited from technology shared under open-source license by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER). The EHT project is grateful to T4Science and Microsemi for their assistance with Hydrogen Masers. This research has made use of NASA's Astrophysics Data System. We gratefully acknowledge the support provided by the extended staff of the ALMA, both from the inception of the ALMA Phasing Project through the observational campaigns of 2017 and 2018. We would like to thank A. Deller and W. Brisken for EHT-specific support with the use of DiFX. We thank J. Delgado for helpful discussions and feedback.

Published
2022

48. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author

Masanori Nakamura, R. Shang, Abelardo Moralejo, A. Rugliancich, Marina Manganaro, Jun Liu, Monika Moscibrodzka, Andreas Specovius, V. Ramakrishnan, S. O'Brien, Michal Ostrowski, Luis C. Ho, Sera Markoff, D. Depaoli, I. Jung-Richardt, Manel Errando, Chiara Righi, S. Panny, Toshiaki Inada, Alexandra J. Tetarenko, Daniela Dorner, Norbert Wex, Nimesh A. Patel, Olivier Hervet, C. Arcaro, Alasdair E. Gent, Yu Wun Wong, Gaia Vanzo, Pierre Brun, Konstancja Satalecka, Stefan Funk, Lorenzo Bellizzi, Michael Lindqvist, Michele Doro, Felix Jankowsky, P. Kaaret, Nicholas R. MacDonald, Lang Cui, P. Temnikov, S. Patel, Sabrina Einecke, Manuel Artero, E. Moretti, Hope Boyce, M. Gaug, Charles F. Gammie, Iryna Lypova, Gisela N. Ortiz-León, Felix Aharonian, Colin J. Lonsdale, Buell T. Jannuzi, Gavin Rowell, M. Bryan, Yvonne Becherini, Aleksandar Popstefanija, M. Pohl, A. Marcowith, Jean-Pierre Ernenwein, H. Alyson Ford, Wystan Benbow, Karen E. Williamson, Daryl Haggard, Hambeleleni Ndiyavala, Tod R. Lauer, Arnaud Mares, Chaitanya Priyadarshi, Michael Punch, Helge Rottmann, J. Zorn, D. Dominis Prester, Bernd Schleicher, M. Minev, Hector Olivares, Ciriaco Goddi, S. Pita, J. Herrera, Alessia Spolon, Léa Jouvin, Na Wang, G. Martí-Devesa, Tomohiko Oka, Kirsty Feijen, E. Do Souto Espiñeira, Ralph Eatough, Johannes Veh, Stefano Gabici, Tomislav Terzić, D. Glawion, Gilles Fontaine, Bradford Benson, C. B. Rulten, Jenni Jormanainen, Jason SooHoo, Michael Titus, Jose Miguel Delgado, Marcos López-Moya, Freek Roelofs, Wlodek Bednarek, M. Lundy, Richard Anantua, Alessandra Lamastra, P. T. Reynolds, Vassil Verguilov, M. Lemoine-Goumard, G. Fichet de Clairfontaine, L. Di Venere, Michael Kreter, Jose Miguel Miranda, Alan L. Roy, Yating Chai, A. López-Oramas, M. Tluczykont, Jacek Niemiec, R. Konno, Tyler Trent, Olaf Reimer, Heino Falcke, Amanpreet Kaur, M. Panter, Narek Sahakyan, Kasper B. Schmidt, A. Carosi, K. Egberts, L. Maraschi, Stefan Cikota, V. Joshi, Koji Noda, Elisa Bernardini, Ye-Fei Yuan, Garrett K. Keating, Fumie Tazaki, Pawel Gliwny, M. Vazquez Acosta, Nicola Giglietto, M. Capasso, Vincent Piétu, Satoshi Fukami, Roman Gold, Elina Lindfors, Satoki Matsushita, A. Lemiere, F. Eichhorn, U. Katz, Yoshinori Yonekura, N. Shafi, Natalia Żywucka, Michael Kramer, M. Palatiello, Daniel Mazin, Samuel Timothy Spencer, Victoria Moreno, Oliver Porth, Julian Sitarek, Kazi L.J. Rygl, Wen Ping Lo, Geoffrey C. Bower, Ilje Cho, S. Fegan, Samuel Zouari, J. M. Paredes, V. Fallah Ramazani, Thomas Murach, Jim Hinton, R. J. White, F. Leone, S. Loporchio, M. de Naurois, Ed Fomalont, Bart Ripperda, Dominique Broguiere, J. Becerra González, Joseph R. Farah, Q. Feng, Andreas Quirrenbach, Taehyun Jung, C. Trichard, Masahiro Teshima, Domenico Tiziani, D. Malyshev, Richard Plambeck, Lynn D. Matthews, Avery E. Broderick, S. Kumar, T. J. Williamson, M. K. Daniel, Sylvia Zhu, P. J. Meintjes, Tjark Miener, Jodi Christiansen, Roger Brissenden, S. Sailer, Dmitry Khangulyan, David Paneque, Thomas P. Krichbaum, Sergey S. Savchenko, Angelo Ricarte, Riaan Steenkamp, T. Chand, J. Dyks, Francesco Dazzi, V. Baghmanyan, Zorawar Wadiasingh, Kazunori Akiyama, Stefan Ohm, C. Levy, Giovanna Ferrara, Makoto Inoue, Jhilik Majumdar, Nobuyuki Sakai, Dieter Horns, Jorge A. Preciado-López, Cornelia Müller, G. Hermann, Regis Terrier, A. J. Chromey, Dominic W. Pesce, Felix M. Pötzl, Mark Gurwell, Alejandro Cruz-Osorio, Ivan Marti-Vidal, Ben Prather, Tom Armstrong, Jongho Park, Matteo Cerruti, Ziri Younsi, Amy Furniss, Chih-Wei Locutus Huang, Lijing Shao, A. Djannati-Ataï, Shoko Koyama, D. Gottschall, P. Vincent, A. Brill, Kenji Toma, Antonios Nathanail, M. Nievas-Rosillo, M. Seglar-Arroyo, C. Delgado Mendez, Mahito Sasada, G. Busetto, Maciek Wielgus, Marcos Santander, Doosoo Yoon, D. A. Sanchez, Hiroki Okino, Christo Venter, Christiaan D. Brinkerink, James Ryan, S. Mićanović, Raquel Fraga-Encinas, Mark G. Rawlings, G. H. Sembroski, G. Principe, Xiang Liu, Karl Friedrich Schuster, Ronald Hesper, L. Sun, Ciro Bigongiari, Ramesh Narayan, M. Strzys, L. Mohrmann, Daniel R. van Rossum, Y. Ohtani, Wu Jiang, Luciano Rezzolla, Nu. Komin, V. A. Acciari, Katherine L. Bouman, Jürgen Besenrieder, Clemens Hoischen, A. A. Zdziarski, Antonio Tutone, Hung Yi Pu, A. Arbet Engels, J.-P. Lenain, A. De Angelis, Tomoya Hirota, R. J. García López, Carlo Romoli, Werner Hofmann, Tuomas Savolainen, Neil M. Nagar, Minfeng Gu, M. Karjalainen, Vitaly Neustroev, A. N. Otte, John F. C. Wardle, Tomoaki Oyama, Jongsoo Kim, Monica Barnard, J. Otero-Santos, R. D. Parsons, Pierre Christian, A. Priyana Noel, A. S. Seyffert, Shami Chatterjee, E. O. Angüner, David A. Green, Ramesh Karuppusamy, Zhiyuan Li, J. Devin, Dominik Elsaesser, F. Giordano, Santiago Ubach, Michael A. Nowak, Y. Kobayashi, F. Di Pierro, Iniyan Natarajan, A. Zech, M. Garczarczyk, Dmitriy Kostunin, Michael Janssen, Giacomo Bonnoli, Mariafelicia De Laurentis, Kuo Liu, G. Emery, Yutaro Kofuji, Antxon Alberdi, Marco Toliman Lucchini, R. A. Ong, Catherine Boisson, Daniel C. M. Palumbo, Stefan Klepser, Stefano Covino, Motoki Kino, Daniel Kerszberg, C. Armand, Maria Haupt, D. Zarić, K. Pfrang, R. López-Coto, M. Zacharias, Jae-Young Kim, Sheperd S. Doeleman, U. Barres de Almeida, Pratik Majumdar, M. V. Fonseca, Mosè Mariotti, G. Lamanna, Alexander Hahn, Sidika Merve Colak, R. J. Tuffs, B. Bi, Juan-Carlos Algaba, L. Oakes, D. Jankowsky, Y. Kajiwara, R. Marx, Bošnjak, John E. Barrett, Kotaro Niinuma, F. D'Ammando, Qingwen Wu, A. Yusafzai, Christian M. Fromm, Chi-kwan Chan, B. De Lotto, M. Kertzman, Manuela Mallamaci, H. Prokoph, Tadayuki Takahashi, Damir Lelas, Victor Doroshenko, E. Kasai, Lea Heckmann, Bong Won Sohn, Francesco Gabriele Saturni, Shiro Ikeda, T. Vuillaume, Laurent Loinard, G. Maurin, M. Füßling, Martin Will, Yi Chen, Gianluca Giavitto, Remo P. J. Tilanus, M. Spir-Jacob, Alessandro Montanari, Thomas Lohse, Tihomir Surić, J. van Scherpenberg, Per Friberg, He Sun, Luca Tosti, Kiyoaki Wajima, E. Ruiz-Velasco, Thomas Bylund, M. Balokovic, Feng Yuan, S. Nozaki, Mischa Breuhaus, Peter Galison, Y. A. Gallant, L. Olivera-Nieto, Dorota Sobczyńska, Maria-Isabel Bernardos, R. Rauth, Izumi Mizuno, Vincent L. Fish, S. G. Jorstad, Tomoki Saito, Giovanni Ceribella, Jacques Muller, J. P. Finley, Stefano Ansoldi, Boris Georgiev, Marcello Giroletti, Arturo I. Gómez-Ruiz, Karl M. Menten, Aristeidis Noutsos, P. deWilt, Junhan Kim, Alejandro Mus Mejías, Q. Remy, Dong-Jin Kim, P. G. Prada Moroni, Robert Wharton, Riccardo Paoletti, R. R. Prado, Zhi-Qiang Shen, S. Paiano, S. Chandra, Andrés Baquero, Anna Barnacka, Lucy Fortson, Wrijupan Bhattacharyya, Marc Ribó, E. de Ona Wilhelmi, Paul T. P. Ho, Yan-Rong Li, Derek Ward-Thompson, M. Scalici, G. Maneva, Constantin Steppa, Dimitrios Psaltis, A.M. Taylor, J. Damascene Mbarubucyeye, Daniel P. Marrone, Karl Mannheim, W. Boland, P. Morris, D. A. Prokhorov, M. Mohamed, Katsuaki Asano, Gernot Maier, Kotaro Moriyama, H. Odaka, M. Büchele, E. Pueschel, Kazuyoshi Nishijima, Christopher J. Duffy, H. M. Schutte, Camilla Maggio, Mark Kettenis, V. D'Elia, Saverio Lombardi, Ramprasad Rao, Ivica Puljak, R. Mirzoyan, V. Sahakian, Guang Yao Zhao, Adrian Biland, F. Werner, Rafal Moderski, Olivier Gentaz, Ullrich Schwanke, James M. Moran, S. Komossa, Yuzhu Cui, A. Jiménez-Rosales, Arash Roshanineshat, S. Ventura, Lindy Blackburn, David J. James, G. Hughes, Hidetoshi Kubo, Mansour Karami, José L. Gómez, P. Reichherzer, Davit Zargaryan, Paul Tiede, Koushik Chatterjee, Chunchong Ni, Roger Deane, Axel Donath, J. Rico, A. W. Chen, A. Fiasson, Jun Yi Koay, T. B. Humensky, Satoko Sawada-Satoh, Isak Delberth Davids, Alan P. Marscher, Alan E. E. Rogers, Rebecca Azulay, Kazuma Ishio, Paul M. Chesler, D. M. Strom, Carlo Vigorito, Marek Jamrozy, G. Pühlhofer, M. de Bony de Lavergne, Roberta Zanin, T. Schweizer, Elisa Prandini, Helene Sol, Rodolfo Carosi, M. Hörbe, T. Tavernier, Mareki Honma, M. Holler, Gordon T. Richards, Armelle Jardin-Blicq, Paolo Marchegiani, Sang-Sung Lee, D. Huber, Ashot Chilingarian, Nikola Godinovic, F. Ait Benkhali, Jason Dexter, Do-Young Byun, Anton Dmytriiev, Massimo Persic, Alicia Fattorini, L. Dirson, Cosimo Nigro, E. Roache, Sargis Gasparyan, S. Schwemmer, Sara Issaoun, Jessica Dempsey, Andrea Santangelo, Włodek Kluźniak, Mel Rose, Huib Jan van Langevelde, D. J. van der Walt, Elisabetta Liuzzo, A. Stamerra, John Hoang, Michelle Tsirou, Wolfgang Rhode, Tomohisa Kawashima, L. A. Antonelli, Carolin Wunderlich, Keiichi Asada, David A. Williams, Joachim Hahn, P. Moriarty, T. M. Crawford, P. Da Vela, L. Rinchiuso, E. Molina, F. Peter Schloerb, Lovro Pavletić, S. Steinmassl, Des Small, Christoph Deil, Stefano Menchiari, Dan Bintley, K. Nakashima, Alice Donini, David H. Hughes, Heinrich J. Völk, Mohanraj Senniappan, K. A. Farrell, M. Renaud, J. A. Barrio, Miriam Lucio Martinez, Rachel Simoni, P. T. O'Brien, E. Colombo, V. Barbosa Martins, M. Orienti, Efthalia Traianou, Lluis Font, B. Machado de Oliveira Fraga, Y. Suda, J. Neilsen, John Conway, Eduardo Ros, Gibwa Musoke, Tarek M. Hassan, J. Bolmont, A. Sinha, Halim Ashkar, M.-H. Grondin, Daniel Nieto, Lab Saha, Fabrizio Tavecchio, Hyunwook Ro, Michael H. Hecht, Markus Böttcher, Antonio Fuentes, Simone Mender, Moritz Hütten, Ue-Li Pen, Yosuke Mizuno, Gopal Narayanan, Lei Huang, H. Abdalla, M. A. Kastendieck, Nicola Marchili, I. Snidaric, S. Sánchez, G. Vasileiadis, Kari Nilsson, Alexander W. Raymond, Greg Lindahl, Gregory Desvignes, Sascha Trippe, Sanae Inoue, Giacomo D'Amico, W. Jin, B. van Soelen, Andrew Chael, Anne Kathrin Baczko, Shunsuke Sakurai, L. Giunti, A. Nayerhoda, Walter Alef, Jamie Holder, Stefano Truzzi, Pablo Peñil, M. J. Lang, Francois Brun, Frank M. Rieger, V. Vitale, George N. Wong, Jirong Mao, S. Caroff, J. Kushida, André Young, Ru-Sen Lu, Daniel Morcuende, Jose Luis Contreras, Kazuhiro Hada, Juan Cortina, C. van Eldik, Pablo Torne, Raymond Blundell, Jarred Gershon Green, C. B. Adams, James M. Cordes, Jonathan Weintroub, Q. Piel, A. Berti, James E. M. Watson, G. Peron, Ken Young, Garret Cotter, Dario Hrupec, Jonathan Mackey, K. Ragan, John E. Carlstrom, Michael Backes, Tim Holch, D. Hadasch, Stawarz, F. Niederwanger, Feryal Özel, Lia Medeiros, A. Weinstein, Mitsunari Takahashi, Manuel Delfino, C. Y. Kuo, Aviad Levis, Francesco Longo, K. Kosack, Konrad Bernlöhr, Jacco Vink, C. Moore, Michael Bremer, Jim Davies, Jadyn Anczarski, Patrick M. Koch, Sabrina Casanova, Ming-Tang Chen, B. Peyaud, Christian Stegmann, Stefan Wagner, C. Perennes, Yasunobu Uchiyama, David Kieda, Chet Ruszczyk, Hiroshi Nagai, M. Curyło, Andrei Lobanov, Ana Babić, E. Moulin, Tomasz Bulik, Britton Jeter, I. Vovk, Martin Makariev, C. van Rensburg, Oscar Blanch, Rocco Lico, Silke Britzen, Misao Sasaki, A. Reimer, V. Poireau, R. Adam, David Ball, Mark Reynolds, D. Miceli, John L. Quinn, Roberto Garcia, J. F. Glicenstein, D. Ribeiro, A. Wierzcholska, Geoffrey B. Crew, Bruno Khelifi, David Sánchez-Arguelles, Ilse van Bemmel, Michael D. Johnson, J. Anton Zensus, Dominik Baack, Manuel Meyer, E. V. Kravchenko, I. Jiménez, Thomas Bronzwaer, Reshmi Mukherjee, D. Berge, C. Giuri, Kleopas Shiningayamwe, Shan Shan Zhao, Yuki Iwamura, A. D. Falcone, Lenka Tomankova, Carsten Kramer, Jan Wagner, Christian Fruck, B. Rudak, Jordy Davelaar, V. Marandon, K. Katarzyński, Roberto Neri, The EHT MWL Science Working Group, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Instituto de RadioAstronomía Milimétrica (IRAM), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Groupe de Physique des Solides (GPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL), Event Horizon Telescope, Fermi-LAT, H.E.S.S., MAGIC, VERITAS, EAVN, High Energy Astrophys. & Astropart. Phys (API, FNWI), API Other Research (FNWI), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Algaba, Jc, Anczarski, J, Asada, K, Balokovic, M, Chandra, S, Cui, Yz, Falcone, Ad, Giroletti, M, Goddi, C, Hada, K, Haggard, D, Jorstad, S, Kaur, A, Kawashima, T, Keating, G, Kim, Jy, Kino, M, Komossa, S, Kravchenko, Ev, Krichbaum, Tp, Lee, S, Lu, R, Lucchini, M, Markoff, S, Neilsen, J, Nowak, Ma, Park, J, Principe, G, Ramakrishnan, V, Reynolds, Mt, Sasada, M, Savchenko, S, Williamson, Ke, Longo, F, Et, Al., University of Michigan, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, Algaba, J. C., Anczarski, J., Asada, K., Balokovic, M., Chandra, S., Cui, Y. -Z., Falcone, A. D., Giroletti, M., Goddi, C., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Keating, G., Kim, J. -Y., Kino, M., Komossa, S., Kravchenko, E. V., Krichbaum, T. P., Lee, S. -S., Lu, R. -S., Lucchini, M., Markoff, S., Neilsen, J., Nowak, M. A., Park, J., Principe, G., Ramakrishnan, V., Reynolds, M. T., Sasada, M., Savchenko, S. S., Williamson, K. E., Akiyama, K., Alberdi, A., Alef, W., Anantua, R., Azulay, R., Baczko, A. -K., Ball, D., Barrett, J., Bintley, D., Benson, B. A., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chan, C. -K., Chatterjee, S., Chatterjee, K., Chen, M. -T., Chen, Y., Chesler, P. M., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Gold, R., Gomez, J. L., Gomez-Ruiz, A. I., Gu, M., Gurwell, M., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jung, T., Karami, M., Karuppusamy, R., Kettenis, M., Kim, D. -J., Kim, J., Koay, J. Y., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Kuo, C. -Y., Lauer, T. R., Levis, A., Li, Y. -R., Li, Z., Lindqvist, M., Lico, R., Lindahl, G., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C., Macdonald, N. R., Mao, J., Marchili, N., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Musoke, G., Mejias, A. M., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Neri, R., Ni, C., Noutsos, A., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Patel, N., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Potzl, F. M., Prather, B., Preciado-Lopez, J. A., Psaltis, D., Pu, H. -Y., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Trent, T., Traianou, E., Trippe, S., Van Bemmel, I., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhao, G. -Y., Zhao, S. -S., D'Ammando, F., Orienti, M., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. A., Anguner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlohr, K., Bi, B., Bottcher, M., Boisson, C., Bolmont, J., De Bony De Lavergne, M., Breuhaus, M., Brun, F., Brun, P., Bryan, M., Buchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chen, A., Cotter, G., Curylo, M., Damascene Mbarubucyeye, J., Davids, I. D., Davies, J., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., De Clairfontaine, G. F., Fontaine, G., Funk, S., Fussling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzynski, K., Katz, U., Khangulyan, D., Khelifi, B., Klepser, S., Kluzniak, W., Komin, N., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Marti-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., De Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., De Ona Wilhelmi, E., Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. P., Prokhorov, D. A., Prokoph, H., Puhlhofer, G., Punch, M., Quirrenbach, A., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., Van Der Walt, D. J., Van Eldik, C., Van Rensburg, C., Van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Volk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Y. W., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., Zywucka, N., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. A., Artero, M., Asano, K., Baack, D., Babic, A., Baquero, A., De Almeida, U. B., Barrio, J. A., Becerra Gonzalez, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bosnjak, Z., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espineira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Garcia Lopez, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinovic, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hutten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jimenez, I., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., Lopez-Coto, R., Lopez-Moya, M., Lopez-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martinez, M., Mazin, D., Menchiari, S., Mender, S., Micanovic, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletic, L., Penil, P., Perennes, C., Persic, M., Moroni, P. G. P., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribo, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Snidaric, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suric, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzic, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zaric, D., Adams, C. B., Benbow, W., Brill, A., Capasso, M., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Errando, M., Farrell, K. A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Giuri, C., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kieda, D., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Otte, A. N., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Rulten, C., Ryan, J. L., Santander, M., Sembroski, G. H., Shang, R., Weinstein, A., Williams, D. A., Williamson, T. J., Hirota, T., Cui, L., Niinuma, K., Ro, H., Sakai, N., Sawada-Satoh, S., Wajima, K., Wang, N., Liu, X., Yonekura, Y., German Research Foundation, Istituto Nazionale di Fisica Nucleare, Swiss National Science Foundation, Ministerio de Ciencia, Innovación y Universidades (España), Department of Atomic Energy (India), University of Tokyo, Japan Society for the Promotion of Science, Ministry of Education and Scientific Research (Romania), Academy of Finland, La Caixa, Croatian Science Foundation, Generalitat de Catalunya, Polish National Agency for Academic Exchange, University of Rijeka, Department of Energy (US), Smithsonian Institution, Astronomy, and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)

Subjects
Accretion, 010504 meteorology & atmospheric sciences, Astronomy, Flux, Astrophysics, 7. Clean energy, 01 natural sciences, Active galactic nuclei, Radio cores, Low-luminosity active galactic nuclei, High energy astrophysics, Astrophysical black holes, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, astro-ph.HE, Radio core, Accretion (meteorology), 520 Astronomie und zugeordnete Wissenschaften, Low-luminosity, active galactic nuclei, Astrophysical black hole, astro-ph.CO, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Active galactic nucleus, High-energy astronomy, astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, F500, Astrophysics::Cosmology and Extragalactic Astrophysics, High energy astrophysic, 0103 physical sciences, Very-long-baseline interferometry, ddc:530, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Event Horizon Telescope, Supermassive black hole, Astronomy and Astrophysics, 530 Physik, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ddc:520, HESS - Abteilung Hinton, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Full list of authors: EHT MWL Science Working Group; Algaba, J. C.; Anczarski, J.; Asada, K.; Baloković, M.; Chandra, S.; Cui, Y. -Z.; Falcone, A. D.; Giroletti, M.; Goddi, C.; Hada, K.; Haggard, D.; Jorstad, S.; Kaur, A.; Kawashima, T.; Keating, G.; Kim, J. -Y.; Kino, M.; Komossa, S.; Kravchenko, E. V.; Krichbaum, T. P.; Lee, S. -S.; Lu, R. -S.; Lucchini, M.; Markoff, S.; Neilsen, J.; Nowak, M. A.; Park, J.; Principe, G.; Ramakrishnan, V.; Reynolds, M. T.; Sasada, M.; Savchenko, S. S.; Williamson, K. E.; Event Horizon Telescope Collaboration; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Anantua, Richard; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David; Barrett, John; Bintley, Dan; Benson, Bradford A.; Blackburn, Lindy; Blundell, Raymond; Boland, Wilfred; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Dominique; Bronzwaer, Thomas; Byun, Do-Young; Carlstrom, John E.; Chael, Andrew; Chan, Chi-Kwan; Chatterjee, Shami; Chatterjee, Koushik; Chen, Ming-Tang; Chen, Yongjun; Chesler, Paul M.; Cho, Ilje; Christian, Pierre; Conway, John E.; Cordes, James M.; Crawford, Thomas M.; Crew, Geoffrey B.; Cruz-Osorio, Alejandro; Davelaar, Jordy; de Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Doeleman, Sheperd S.; Eatough, Ralph P.; Falcke, Heino; Farah, Joseph; Fish, Vincent L.; Fomalont, Ed; Ford, H. Alyson; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Fuentes, Antonio; Galison, Peter; Gammie, Charles F.; García, Roberto; Gentaz, Olivier; Georgiev, Boris; Gold, Roman; Gómez, José L.; Gómez-Ruiz, Arturo I.; Gu, Minfeng; Gurwell, Mark; Hecht, Michael H.; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Ikeda, Shiro; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jiménez-Rosales, Alejandra; Johnson, Michael D.; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kettenis, Mark; Kim, Dong-Jin; Kim, Jongsoo; Kim, Junhan; Koay, Jun Yi; Kofuji, Yutaro; Koch, Patrick M.; Koyama, Shoko; Kramer, Michael; Kramer, Carsten; Kuo, Cheng-Yu; Lauer, Tod R.; Levis, Aviad; Li, Yan-Rong; Li, Zhiyuan; Lindqvist, Michael; Lico, Rocco; Lindahl, Greg; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin; MacDonald, Nicholas R.; Mao, Jirong; Marchili, Nicola; Marrone, Daniel P.; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Medeiros, Lia; Menten, Karl M.; Mizuno, Izumi; Mizuno, Yosuke; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Müller, Cornelia; Musoke, Gibwa; Mejías, Alejandro Mus; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Nathanail, Antonios; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Okino, Hiroki; Olivares, Héctor; Ortiz-León, Gisela N.; Oyama, Tomoaki; Özel, Feryal; Palumbo, Daniel C. M.; Patel, Nimesh; Pen, Ue-Li; Pesce, Dominic W.; Piétu, Vincent; Plambeck, Richard; Popstefanija, Aleksandar; Porth, Oliver; Pötzl, Felix M.; Prather, Ben; Preciado-López, Jorge A.; Psaltis, Dimitrios; Pu, Hung-Yi; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ricarte, Angelo; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Rose, Mel; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruszczyk, Chet; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; Soohoo, Jason; Sun, He; Tazaki, Fumie; Tetarenko, Alexandra J.; Tiede, Paul; Tilanus, Remo P. J.; Titus, Michael; Toma, Kenji; Torne, Pablo; Trent, Tyler; Traianou, Efthalia; Trippe, Sascha; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Ward-Thompson, Derek; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wong, George N.; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhao, Guang-Yao; Zhao, Shan-Shan; Fermi Large Area Telescope Collaboration; Principe, G.; Giroletti, M.; D'Ammando, F.; Orienti, M.; H. E. S. S. Collaboration; Abdalla, H.; Adam, R.; Aharonian, F.; Benkhali, F. Ait; Angüner, E. O.; Arcaro, C.; Armand, C.; Armstrong, T.; Ashkar, H.; Backes, M.; Baghmanyan, V.; Barbosa Martins, V.; Barnacka, A.; Barnard, M.; Becherini, Y.; Berge, D.; Bernlöhr, K.; Bi, B.; Böttcher, M.; Boisson, C.; Bolmont, J.; de Lavergne, M. De Bony; Breuhaus, M.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Bylund, T.; Caroff, S.; Carosi, A.; Casanova, S.; Chand, T.; Chen, A.; Cotter, G.; Curyło, M.; Damascene Mbarubucyeye, J.; Davids, I. D.; Davies, J.; Deil, C.; Devin, J.; Dewilt, P.; Dirson, L.; Djannati-Ataï, A.; Dmytriiev, A.; Donath, A.; Doroshenko, V.; Duffy, C.; Dyks, J.; Egberts, K.; Eichhorn, F.; Einecke, S.; Emery, G.; Ernenwein, J. -P.; Feijen, K.; Fegan, S.; Fiasson, A.; de Clairfontaine, G. Fichet; Fontaine, G.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Giavitto, G.; Giunti, L.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M. -H.; Hahn, J.; Haupt, M.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Hörbe, M.; Horns, D.; Huber, D.; Jamrozy, M.; Jankowsky, D.; Jankowsky, F.; Jardin-Blicq, A.; Joshi, V.; Jung-Richardt, I.; Kasai, E.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Khangulyan, D.; Khélifi, B.; Klepser, S.; Kluźniak, W.; Komin, Nu.; Konno, R.; Kosack, K.; Kostunin, D.; Kreter, M.; Lamanna, G.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J. -P.; Levy, C.; Lohse, T.; Lypova, I.; Mackey, J.; Majumdar, J.; Malyshev, D.; Malyshev, D.; Marandon, V.; Marchegiani, P.; Marcowith, A.; Mares, A.; Martí-Devesa, G.; Marx, R.; Maurin, G.; Meintjes, P. J.; Meyer, M.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Montanari, A.; Moore, C.; Morris, P.; Moulin, E.; Muller, J.; Murach, T.; Nakashima, K.; Nayerhoda, A.; de Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Olivera-Nieto, L.; de Ona Wilhelmi, E.; Ostrowski, M.; Panter, M.; Panny, S.; Parsons, R. D.; Peron, G.; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Noel, A. Priyana; Prokhorov, D. A.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Rauth, R.; Reichherzer, P.; Reimer, A.; Reimer, O.; Remy, Q.; Renaud, M.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Ruiz-Velasco, E.; Sahakian, V.; Sailer, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Scalici, M.; Schutte, H. M.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Senniappan, M.; Seyffert, A. S.; Shafi, N.; Shiningayamwe, K.; Simoni, R.; Sinha, A.; Sol, H.; Specovius, A.; Spencer, S.; Spir-Jacob, M.; Stawarz, Ł.; Sun, L.; Steenkamp, R.; Stegmann, C.; Steinmassl, S.; Steppa, C.; Takahashi, T.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tiziani, D.; Tluczykont, M.; Tomankova, L.; Trichard, C.; Tsirou, M.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Vincent, P.; Vink, J.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Watson, J.; Werner, F.; White, R.; Wierzcholska, A.; Wong, Yu Wun; Yusafzai, A.; Zacharias, M.; Zanin, R.; Zargaryan, D.; Zdziarski, A. A.; Zech, A.; Zhu, S. J.; Zorn, J.; Zouari, S.; Żywucka, N.; MAGIC Collaboration; Acciari, V. A.; Ansoldi, S.; Antonelli, L. A.; Engels, A. Arbet; Artero, M.; Asano, K.; Baack, D.; Babić, A.; Baquero, A.; de Almeida, U. Barres; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bellizzi, L.; Bernardini, E.; Bernardos, M.; Berti, A.; Besenrieder, J.; Bhattacharyya, W.; Bigongiari, C.; Biland, A.; Blanch, O.; Bonnoli, G.; Bošnjak, Ž.; Busetto, G.; Carosi, R.; Ceribella, G.; Cerruti, M.; Chai, Y.; Chilingarian, A.; Cikota, S.; Colak, S. M.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; D'Amico, G.; D'Elia, V.; da Vela, P.; Dazzi, F.; de Angelis, A.; de Lotto, B.; Delfino, M.; Delgado, J.; Delgado Mendez, C.; Depaoli, D.; di Pierro, F.; di Venere, L.; Do Souto Espiñeira, E.; Dominis Prester, D.; Donini, A.; Dorner, D.; Doro, M.; Elsaesser, D.; Ramazani, V. Fallah; Fattorini, A.; Ferrara, G.; Fonseca, M. V.; Font, L.; Fruck, C.; Fukami, S.; García López, R. J.; Garczarczyk, M.; Gasparyan, S.; Gaug, M.; Giglietto, N.; Giordano, F.; Gliwny, P.; Godinović, N.; Green, J. G.; Green, D.; Hadasch, D.; Hahn, A.; Heckmann, L.; Herrera, J.; Hoang, J.; Hrupec, D.; Hütten, M.; Inada, T.; Inoue, S.; Ishio, K.; Iwamura, Y.; Jiménez, I.; Jormanainen, J.; Jouvin, L.; Kajiwara, Y.; Karjalainen, M.; Kerszberg, D.; Kobayashi, Y.; Kubo, H.; Kushida, J.; Lamastra, A.; Lelas, D.; Leone, F.; Lindfors, E.; Lombardi, S.; Longo, F.; López-Coto, R.; López-Moya, M.; López-Oramas, A.; Loporchio, S.; Machado de Oliveira Fraga, B.; Maggio, C.; Majumdar, P.; Makariev, M.; Mallamaci, M.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Menchiari, S.; Mender, S.; Mićanović, S.; Miceli, D.; Miener, T.; Minev, M.; Miranda, J. M.; Mirzoyan, R.; Molina, E.; Moralejo, A.; Morcuende, D.; Moreno, V.; Moretti, E.; Neustroev, V.; Nigro, C.; Nilsson, K.; Nishijima, K.; Noda, K.; Nozaki, S.; Ohtani, Y.; Oka, T.; Otero-Santos, J.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Pavletić, L.; Peñil, P.; Perennes, C.; Persic, M.; Moroni, P. G. Prada; Prandini, E.; Priyadarshi, C.; Puljak, I.; Rhode, W.; Ribó, M.; Rico, J.; Righi, C.; Rugliancich, A.; Saha, L.; Sahakyan, N.; Saito, T.; Sakurai, S.; Satalecka, K.; Saturni, F. G.; Schleicher, B.; Schmidt, K.; Schweizer, T.; Sitarek, J.; Šnidarić, I.; Sobczynska, D.; Spolon, A.; Stamerra, A.; Strom, D.; Strzys, M.; Suda, Y.; Surić, T.; Takahashi, M.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Teshima, M.; Tosti, L.; Truzzi, S.; Tutone, A.; Ubach, S.; van Scherpenberg, J.; Vanzo, G.; Vazquez Acosta, M.; Ventura, S.; Verguilov, V.; Vigorito, C. F.; Vitale, V.; Vovk, I.; Will, M.; Wunderlich, C.; Zarić, D.; VERITAS Collaboration; Adams, C. B.; Benbow, W.; Brill, A.; Capasso, M.; Christiansen, J. L.; Chromey, A. J.; Daniel, M. K.; Errando, M.; Farrell, K. A.; Feng, Q.; Finley, J. P.; Fortson, L.; Furniss, A.; Gent, A.; Giuri, C.; Hassan, T.; Hervet, O.; Holder, J.; Hughes, G.; Humensky, T. B.; Jin, W.; Kaaret, P.; Kertzman, M.; Kieda, D.; Kumar, S.; Lang, M. J.; Lundy, M.; Maier, G.; Moriarty, P.; Mukherjee, R.; Nieto, D.; Nievas-Rosillo, M.; O'Brien, S.; Ong, R. A.; Otte, A. N.; Patel, S.; Pfrang, K.; Pohl, M.; Prado, R. R.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Ribeiro, D.; Richards, G. T.; Roache, E.; Rulten, C.; Ryan, J. L.; Santander, M.; Sembroski, G. H.; Shang, R.; Weinstein, A.; Williams, D. A.; Williamson, T. J.; Eavn Collaboration; Hirota, Tomoya; Cui, Lang; Niinuma, Kotaro; Ro, Hyunwook; Sakai, Nobuyuki; Sawada-Satoh, Satoko; Wajima, Kiyoaki; Wang, Na; Liu, Xiang; Yonekura, Yoshinori, In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded., The financial support of the German BMBF, MPG and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish Ministerio de Ciencia e Innovacion (MICINN) (FPA2017-87859-P, FPA2017-85668-P, FPA2017- 82729-C6-5-R, FPA2017-90566-REDC, PID2019-104114RBC31, PID2019-104114RB-C32, PID2019-105510GB-C31,PID 2019-107847RB-C41, PID2019-107847RB-C42, PID2019- 107988GB-C22); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-268/16.12.2019 and the Academy of Finland grant No. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2016-0588 and CEX2019- 000920-S, and “Maria de Maeztu” CEX2019-000918-M, the Unidad de Excelencia “Maria de Maeztu” MDM-2015-0509- 18-2 and the “la Caixa” Foundation (fellowship LCF/BQ/ PI18/11630012) and by the CERCA program of the Generalitat de Catalunya; by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02; by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3; the Polish National Research Centre grant UMO-2016/22/M/ST9/00382; and by the Brazilian MCTIC, CNPq, and FAPERJ. This research is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, and by the Helmholtz Association in Germany. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy’s Office of Science, and resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument.

Published
2021

49. Gravitational Test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole

Author

Jae-Young Kim, Olivier Gentaz, Kazunori Akiyama, Mark Gurwell, Maciek Wielgus, David J. James, Ivan Marti-Vidal, Aristeidis Noutsos, Raquel Fraga-Encinas, Mark G. Rawlings, Jessica Dempsey, Alan P. Marscher, Mark Kettenis, Michael Bremer, Makoto Inoue, André Young, Huib Jan van Langevelde, John F. C. Wardle, Tomoaki Oyama, Sang-Sung Lee, Motoki Kino, Jongho Park, Dan Bintley, Monika Moscibrodzka, Paul T. P. Ho, F. Peter Schloerb, Alejandro Mus Mejías, Robert Wharton, Vincent Piétu, Wen Ping Lo, Geoffrey C. Bower, Zhiyuan Li, Derek Ward-Thompson, Pablo Torne, Chih-Wei Locutus Huang, Lijing Shao, Christiaan D. Brinkerink, Keiichi Asada, Karl Friedrich Schuster, Ronald Hesper, Koushik Chatterjee, Venkatessh Ramakrishnan, John E. Barrett, Bart Ripperda, Dominique Broguiere, Ye-Fei Yuan, Doosoo Yoon, Alan E. E. Rogers, Rebecca Azulay, Des Small, Ramesh Karuppusamy, Ilse van Bemmel, Garrett K. Keating, Tuomas Savolainen, Neil M. Nagar, Roger Brissenden, Colin J. Lonsdale, Chi-kwan Chan, Arash Roshanineshat, Michael D. Johnson, Dimitrios Psaltis, Daniel P. Marrone, Sera Markoff, Izumi Mizuno, Feng Yuan, Vincent L. Fish, Ue-Li Pen, Yosuke Mizuno, Per Friberg, Junhan Kim, Norbert Wex, Mahito Sasada, John E. Carlstrom, Roberto Neri, Jun Liu, Ben Prather, David Ball, Wu Jiang, Svetlana G. Jorstad, S. Sánchez, Shoko Koyama, Alan L. Roy, Nimesh A. Patel, Ramesh Narayan, Lia Medeiros, W. Boland, Sascha Trippe, Luis C. Ho, C. Y. Kuo, Ramprasad Rao, Efthalia Traianou, Pierre Christian, Antxon Alberdi, Aleksandar Popstefanija, Helge Rottmann, Roberto Garcia, Zhi-Qiang Shen, Iniyan Natarajan, Patrick M. Koch, Hector Olivares, Mariafelicia De Laurentis, Kuo Liu, Ralph Eatough, Ming-Tang Chen, Carsten Kramer, David H. Hughes, Geoffrey B. Crew, Christian M. Fromm, Hiroshi Nagai, Andrei Lobanov, John Conway, Eduardo Ros, Rocco Lico, David Sánchez-Arguelles, Jan Wagner, Cornelia Müller, A. Jiménez-Rosales, Sara Issaoun, Ed Fomalont, Michael Lindqvist, Michael Kramer, Ilje Cho, R. P. J. Tilanus, Taehyun Jung, Elisabetta Liuzzo, Lei Huang, Ciriaco Goddi, Jun Yi Koay, Jordy Davelaar, Mansour Karami, Thomas P. Krichbaum, Tyler Trent, Andrew Chael, José L. Gómez, Satoki Matsushita, Bong Won Sohn, Daniel R. van Rossum, Kazi L.J. Rygl, Charles F. Gammie, Yuzhu Cui, Gibwa Musoke, Yan-Rong Li, Jorge A. Preciado-López, Kotaro Moriyama, Jason Dexter, Do-Young Byun, Thomas Bronzwaer, G. Desvignes, Roger Deane, Walter Alef, Benjamin R. Ryan, Michael Janssen, Minfeng Gu, Mislav Baloković, Shami Chatterjee, Jongsoo Kim, George N. Wong, Jirong Mao, Shan Shan Zhao, Mareki Honma, Daniel C. M. Palumbo, Kazuhiro Hada, Z. Younsi, Ken H. Young, Qingwen Wu, Lindy Blackburn, Hiroki Okino, Richard L. Plambeck, Michael Titus, Freek Roelofs, James M. Moran, Mel Rose, Tomohisa Kawashima, Jason SooHoo, Fumie Tazaki, Heino Falcke, Yi Chen, Feryal Özel, Gopal Narayanan, Alexander W. Raymond, Chet Ruszczyk, Silke Britzen, Buell T. Jannuzi, Tod R. Lauer, Ru-Sen Lu, James M. Cordes, Jonathan Weintroub, Astronomy, Ministerio de Economía y Competitividad (España), European Commission, Junta de Andalucía, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Instituto de RadioAstronomía Milimétrica (IRAM), Event Horizon Telescope, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, High Energy Astrophys. & Astropart. Phys (API, FNWI), Gravitation and Astroparticle Physics Amsterdam, Psaltis, D., Medeiros, L., Christian, P., Ozel, F., Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Ball, D., Balokovic, M., Barrett, J., Bintley, D., Blackburn, L., Boland, W., Bower, G. C., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broguiere, D., Bronzwaer, T., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chan, C. -K., Chatterjee, S., Chatterjee, K., Chen, M. -T., Chen, Y., Cho, I., Conway, J. E., Cordes, J. M., Crew, G. B., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Eatough, R. P., Falcke, H., Fish, V. L., Fomalont, E., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Gammie, C. F., Garcia, R., Gentaz, O., Goddi, C., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Krichbaum, T. P., Kuo, C. -Y., Lauer, T. R., Lee, S. -S., Li, Y. -R., Li, Z., Lindqvist, M., Lico, R., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Lonsdale, C., Lu, R. -S., Mao, J., Markoff, S., Marrone, D. P., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Mizuno, Y., Mizuno, I., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Musoke, G., Mus Mejias, A., Nagai, H., Nagar, N. M., Narayan, R., Narayanan, G., Natarajan, I., Neri, R., Noutsos, A., Okino, H., Olivares, H., Oyama, T., Palumbo, D. C. M., Park, J., Patel, N., Pen, U. -L., Pietu, V., Plambeck, R., Popstefanija, A., Prather, B., Preciado-Lopez, J. A., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Ryan, B. R., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Tazaki, F., Tilanus, R. P. J., Titus, M., Torne, P., Trent, T., Traianou, E., Trippe, S., Van Bemmel, I., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Wardle, J., Ward-Thompson, D., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., and Zhao, S. -S.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Event Horizon Telescope, Physics, Gravitational wave, Astronomy, Kerr metric, FOS: Physical sciences, General Physics and Astronomy, General Relativity and Quantum Cosmology (gr-qc), Gravitation and Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Black hole, Gravitation, 0103 physical sciences, Metric (mathematics), Shadow, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Statistical physics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010306 general physics, Astrophysics - High Energy Astrophysical Phenomena, Parametric statistics
Abstract

All authors: Psaltis, Dimitrios; Medeiros, Lia; Christian, Pierre; Özel, Feryal; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Asada, Keiichi; Azulay, Rebecca; Ball, David; Baloković, Mislav; Barrett, John; Bintley, Dan; Blackburn, Lindy; Boland, Wilfred; Bower, Geoffrey C.; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke Broguiere, Dominique; Bronzwaer, Thomas; Byun, Do-Young; Carlstrom, John E.; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Shami; Chatterjee, Koushik; Chen, Ming-Tang; Chen, Yongjun; Cho, Ilje; Conway, John E.; Cordes, James M.; Crew, Geoffrey B.; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Dexter, Jason; Eatough, Ralph P.; Falcke, Heino; Fish, Vincent L.; Fomalont, Ed; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Gammie, Charles F.; García, Roberto; Gentaz, Olivier; Goddi, Ciriaco; Gómez, José L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Inoue, Makoto; Issaoun, Sara; James, David J.; Jannuzi, Buell T.; Janssen, Michael; Jiang, Wu; Jimenez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Jung, Taehyun; Karami, Mansour; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Jae-Young; Kim, Junhan; Kim, Jongsoo; Kino, Motoki; Koay, Jun Yi; Koch, Patrick M.; Koyama, Shoko; Kramer, Michael; Kramer, Carsten; Krichbaum, Thomas P.; Kuo, Cheng-Yu; Lauer, Tod R.; Lee, Sang-Sung; Li, Yan-Rong; Li, Zhiyuan; Lindqvist, Michael; Lico, Rocco; Liu, Jun; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Lonsdale, Colin; Lu, Ru-Sen; Mao, Jirong; Markoff, Sera; Marrone, Daniel P.; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Mizuno, Yosuke; Mizuno, Izumi; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Müller, Cornelia; Musoke, Gibwa; Mus Mejías, Alejandro; Nagai, Hiroshi; Nagar, Neil M.; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Neri, Roberto; Noutsos, Aristeidis; Okino, Hiroki; Olivares, Héctor; Oyama, Tomoaki; Palumbo, Daniel C. M.; Park, Jongho; Patel, Nimesh; Pen, Ue-Li; Piétu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Prather, Ben; Preciado-López, Jorge A.; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Rose, Mel; Roshanineshat, Arash; Rottmann, Helge; Roy, Alan L.; Ruszczyk, Chet; Ryan, Benjamin R.; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Sasada, Mahito; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Tazaki, Fumie; Tilanus, Remo P. J.; Titus, Michael; Torne, Pablo; Trent, Tyler; Traianou, Efthalia; Trippe, Sascha; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Wardle, John; Ward-Thompson, Derek; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wong, George N.; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zhao, Shan-Shan; EHT Collaboration, The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements. We use numerical calculations of regular, parametric, non-Kerr metrics to identify the common characteristic among these different parametrizations that control the predicted shadow size. We show that the shadow-size measurements place significant constraints on deviation parameters that control the second post-Newtonian and higher orders of each metric and are, therefore, inaccessible to weak-field tests. The new constraints are complementary to those imposed by observations of gravitational waves from stellar-mass sources. © 2020 American Physical Society., The authors of the present paper thank the following organizations and programs: the Academy of Finland (Projects No. 274477, No. 284495, No. 312496); the Advanced European Network of E-infrastructures for Astronomy with the SKA (AENEAS) project, supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under Grant Agreement No. 731016; the Alexander von Humboldt Stiftung; the Black Hole Initiative at Harvard University, through a grant (No. 60477) from the John Templeton Foundation; the China Scholarship Council; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT, Chile, via PIA ACT172033, Fondecyt Projects No. 1171506 and No. 3190878, BASAL AFB-170002, ALMA-conicyt 31140007); Consejo Nacional de Ciencia y Tecnologia (CONACYT, Mexico, Projects No. 104497, No. 275201, No. 279006, No. 281692); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Direccion General de Asuntos del Personal Academico, Universidad Nacional Autonoma de Mexico (DGAPA-UNAM, project IN112417); the European Research Council Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (Grant No. 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177 and GenT Program (project CIDEGENT/2018/021); the Gordon and Betty Moore Foundation (Grants No. GBMF-3561, No. GBMF-5278); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; the Jansky Fellowship program of the National Radio Astronomy Observatory (NRAO); the Japanese Government (Monbukagakusho:MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, Grants No. QYZDJ-SSW-SLH057, No. QYZDJSSW-SYS008, No. ZDBS-LY-SLH011); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (Grants No. 18KK0090, No. JP18K13594, No. JP18K03656, No. JP18H03721, No. 18K03709, No. 18H01245, No. 25120007); the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M-001-011, 106-2119-M-001-027, 107-2119-M-001-017, 107-2119-M-001-020, and 107-2119-M-110-005); the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator Grant No. 80NSSC17K0649 and Hubble Fellowship Grant No. HST-HF2-51431.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under Contract No. NAS5-26555); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (Grants No. 2016YFA0400704, No. 2016YFA0400702); the National Science Foundation (NSF, Grants No. AST-0096454, No. AST-0352953, No. AST-0521233, No. AST-0705062, No. AST0905844, No. AST-0922984, No. AST-1126433, No. AST-1140030, No. DGE-1144085, No. AST-1207704, No. AST-1207730, No. AST-1207752, No. MRI-1228509, No. OPP-1248097, No. AST-1310896, No. AST-1312651, No. AST-1337663, No. AST-1440254, No. AST-1555365, No. AST-1715061, No. AST-1615796, No. AST-1716327, No. OISE-1743747, No. AST-1816420); the Natural Science Foundation of China (Grants No. 11573051, No. 11633006, No. 11650110427, No. 10625314, No. 11721303, No. 11725312, No. 11933007); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: Grants No. NRF-2015H1A2A1033752, No. 2015-R1D1A1A01056807, the Korea Research Fellowship Program: NRF-2015H1D3A1066561); the Netherlands Organization for Scientific Research (NWO) VICI award (Grant No. 639.043.513) and Spinoza Prize SPI 78-409; the New Scientific Frontiers with Precision Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under Grant No. 2017-00648) the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Russian Science Foundation (Grant No. 17-12-01029); the Spanish Ministerio de Economia y Competitividad (Grants No. AYA2015-63939-C2-1-P, No. AYA2016-80889-P, No. PID2019-108995GB-C21); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709); the Toray Science Foundation; the Consejeria de Economia, Conocimiento, Empresas y Universidad of the Junta de Andalucia (Grant No. P18-FR-1769), the Consejo Superior de Investigaciones Cientificas (Grant No. 2019AEP112); the U.S. Department of Energy (DOE) through the Los Alamos National Laboratory [operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. DOE (Contract No. 89233218CNA000001)]; the Italian Ministero dell'Istruzione, dell'Universita e della Ricerca through the grant Progetti Premiali 2012-iALMA (CUP C52I13000140001); the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 730562 RadioNet; ALMA North America Development Fund; the Academia Sinica;Chandra TM6-17006X; the GenT Program (Generalitat Valenciana) Project CIDEGENT/2018/021. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF Grant No. ACI-1548562, and CyVerse, supported by NSF Grants No. DBI-0735191, No. DBI-1265383, and No. DBI-1743442. We thank the staff at the participating observatories, correlation centers, and institutions for their enthusiastic support. ALMA is a partnership of the European Southern Observatory (ESO; Europe, representing its member states), NSF, and National Institutes of Natural Sciences of Japan, together with National Research Council (Canada), Ministry of Science and Technology (MOST; Taiwan), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), and Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities, Inc. (AUI)/NRAO, and the National Astronomical Observatory of Japan (NAOJ). The NRAO is a facility of the NSF operated under cooperative agreement by AUI. APEX is a collaboration between the Max-Planck-Institut fur Radioastronomie (Germany), ESO, and the Onsala Space Observatory (Sweden). The SMA is a joint project between the SAO and ASIAA and is funded by the Smithsonian Institution and the Academia Sinica. The JCMT is operated by the East Asian Observatory on behalf of the NAOJ, ASIAA, and KASI, as well as the Ministry of Finance of China, Chinese Academy of Sciences, and the National Key R&D Program (No. 2017YFA0402700) of China. Additional funding support for the JCMT is provided by the Science and Technologies Facility Council (UK) and participating universities in the UK and Canada. The LMT is a project operated by the Instituto Nacional de Astrofisica, Optica, y Electronica (Mexico) and the University of Massachusetts at Amherst (USA). The IRAM 30-m telescope on Pico Veleta, Spain, is operated by IRAM and supported by CNRS (Centre National de la Recherche Scientifique, France), MPG (Max-PlanckGesellschaft, Germany) and IGN (Instituto Geografico Nacional, Spain). The SMT is operated by the Arizona Radio Observatory, a part of the Steward Observatory of the University of Arizona, with financial support of operations from the State of Arizona and financial support for instrumentation development from the NSF. The SPT is supported by the National Science Foundation through Grant No. PLR-1248097. Partial support is also provided by the NSF Physics Frontier Center Grant No. PHY1125897 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation and the Gordon and Betty Moore Foundation Grant No. GBMF 947. The SPT hydrogen maser was provided on loan from the GLT, courtesy of ASIAA. The EHTC has received generous donations of FPGA chips from Xilinx Inc., under the Xilinx University Program. The EHTC has benefited from technology shared under open-source license by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER). The EHT project is grateful to T4Science and Microsemi for their assistance with hydrogen masers. This research has made use of NASA's Astrophysics Data System. We gratefully acknowledge the support provided by the extended staff of the ALMA, both from the inception of the ALMA Phasing Project through the observational campaigns of 2017 and 2018. We would like to thank A. Deller and W. Brisken for EHT-specific support with the use of DiFX. We acknowledge the significance that Maunakea, where the SMA and JCMT EHT stations are located, has for the indigenous Hawaiian people.

Published
2020

50. THEMIS: A Parameter Estimation Framework for the Event Horizon Telescope

Author

Jessica Dempsey, Masanori Nakamura, Elisabetta Liuzzo, Michael Kramer, Oliver Porth, Michael Bremer, Walter Alef, Iniyan Natarajan, Thomas P. Krichbaum, Aleksandar Popstefanija, Helge Rottmann, Koushik Chatterjee, F. Peter Schloerb, Rebecca Azulay, Lynn D. Matthews, Avery E. Broderick, Dominic W. Pesce, Charles F. Gammie, Karl Friedrich Schuster, Ronald Hesper, Daniel R. van Rossum, Thomas Bronzwaer, Minfeng Gu, Satoki Matsushita, Ramesh Karuppusamy, Kazi L.J. Rygl, Katherine L. Bouman, R. P. Eatough, Norbert Wex, Jonathan Weintroub, Chet Ruszczyk, Ilje Cho, Andrei P. Lobanov, Dan Bintley, Yan-Rong Li, Alan E. E. Rogers, Sara Issaoun, Chih-Wei Locutus Huang, Lijing Shao, Christiaan D. Brinkerink, Jorge A. Preciado-López, Michael Lindqvist, Kazunori Akiyama, Makoto Inoue, George N. Wong, Wen Ping Lo, Geoffrey C. Bower, Shan Shan Zhao, Maciek Wielgus, James M. Moran, Laurent Loinard, Bart Ripperda, S. Sánchez, Hector Olivares, Raquel Fraga-Encinas, Mark G. Rawlings, Mark Gurwell, Ivan Marti-Vidal, Dominique Broguiere, Zhiqiang Shen, Mariafelicia De Laurentis, John E. Carlstrom, Carsten Kramer, Kuo Liu, A. Jiménez-Rosales, Per Friberg, Yi Chen, Kazuhiro Hada, Huib Jan van Langevelde, Ciriaco Goddi, Feng Yuan, Izumi Mizuno, Jan Wagner, Vincent L. Fish, Hung Yi Pu, Tomoaki Oyama, Sheperd S. Doeleman, Ed Fomalont, Boris Georgiev, Jordy Davelaar, Hiroshi Nagai, Doosoo Yoon, Motoki Kino, Remo P. J. Tilanus, Michael Janssen, Michael Titus, Paul Tiede, Jirong Mao, Colin J. Lonsdale, Mel Rose, Freek Roelofs, W. Boland, Ramprasad Rao, Mansour Karami, José L. Gómez, John E. Barrett, Heino Falcke, Guang-Yao Zhao, Peter Galison, Ilse van Bemmel, C. Y. Kuo, Mislav Baloković, Shami Chatterjee, Robert Wharton, Keiichi Asada, James M. Cordes, Ken H. Young, Michael D. Johnson, Mareki Honma, Monika Moscibrodzka, Olivier Gentaz, Ziyan Zhu, Wu Jiang, Des Small, Jason SooHoo, Svetlana G. Jorstad, Paul T. P. Ho, Silke Britzen, J. Anton Zensus, Zhiyuan Li, Ue-Li Pen, Yosuke Mizuno, David J. James, Vincent Piétu, Tomohisa Kawashima, Ming-Tang Chen, Roberto Garcia, Nicholas R. MacDonald, Roman Gold, Gisela N. Ortiz-León, Sascha Trippe, Gopal Narayanan, Alexander W. Raymond, Gregory Desvignes, Venkatessh Ramakrishnan, Anne Kathrin Baczko, Geoffrey B. Crew, Alan P. Marscher, Bong Won Sohn, Fumie Tazaki, André Young, Ru-Sen Lu, Benjamin R. Ryan, Roberto Neri, Pablo Torne, David Sánchez-Arguelles, John Wardle, Qingwen Wu, Michael H. Hecht, Chunchong Ni, Christian M. Fromm, Lei Huang, Cornelia Müller, Efthalia Traianou, Luis C. Ho, John Conway, Eduardo Ros, Sang-Sung Lee, Andrew Chael, Jongho Park, Ye-Fei Yuan, Hiroki Okino, Richard L. Plambeck, Ziri Younsi, Tuomas Savolainen, Neil M. Nagar, Luciano Rezzolla, Jongsoo Kim, Daniel C. M. Palumbo, Lindy Blackburn, Yuzhu Cui, Ben Prather, Shoko Koyama, Roger Deane, Patrick M. Koch, Britton Jeter, Rocco Lico, Kenji Toma, Do-Young Byun, Antxon Alberdi, Jun Yi Koay, Shuichiro Tsuda, Jae-Young Kim, David H. Hughes, Karl M. Menten, Aristeidis Noutsos, Taehyun Jung, Mark Kettenis, Kotaro Moriyama, Roger Brissenden, Mahito Sasada, Ramesh Narayan, Garrett K. Keating, Perimeter Institute for Theoretical Physics, National Radio Astronomy Observatory Socorro, CSIC, Max Planck Institute for Radio Astronomy, Academia Sinica - Institute of Astronomy and Astrophysics, Harvard University, Massachusetts Institute of Technology, East Asian Observatory, Nederlandse Onderzoekschool voor Astronomie, Academia Sinica, Institut de Radio Astronomie Millimétrique, Radboud University Nijmegen, Korea Astronomy and Space Science Institute, University of Chicago, Cornell University, University of Amsterdam, CAS - Shanghai Astronomical Observatory, Chalmers University of Technology, National Astronomical Observatory of Japan, Goethe University Frankfurt, University of Pretoria, University of Illinois at Urbana-Champaign, University of Groningen, Peking University, Instituto Nacional de Astrofisica Optica y Electronica, Max Planck Institute for Extraterrestrial Physics, St. Petersburg State University, Joint Institute for VLBI in Europe, National Sun Yat-sen University, CAS - Institute of High Energy Physics, Nanjing University, National Institute for Astrophysics, Universidad Nacional Autónoma de México, Chinese Academy of Sciences, Boston University, University of Valencia, Universidad de Concepción, University of Massachusetts, Rhodes University, University of California Berkeley, University of Arizona, Los Alamos National Laboratory, Instituto de Radioastronomía Milimétrica, Anne Lähteenmäki Group, Tohoku University, Seoul National University, Brandeis University, Huazhong University of Science and Technology, University of Science and Technology of China, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University, High Energy Astrophys. & Astropart. Phys (API, FNWI), European Research Council, Academy of Finland, European Commission, Gordon and Betty Moore Foundation, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), Ministry of Education, Culture, Sports, Science and Technology (Japan), Japan Society for the Promotion of Science, National Key Research and Development Program (China), Leverhulme Trust, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), Natural Sciences and Engineering Research Council of Canada, National Science Foundation (US), National Research Foundation of Korea, Netherlands Organization for Scientific Research, Swedish Research Council, Ministry of Research, Technology and Higher Education of the Republic of Indonesia, Russian Science Foundation, Ministerio de Economía y Competitividad (España), Department of Energy (US), Ministero dell'Economia e delle Finanze, National Natural Science Foundation of China, Ministero dell'Istruzione, dell'Università e della Ricerca, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Instituto de RadioAstronomía Milimétrica (IRAM), Event Horizon Telescope, Astronomy, Broderick, A. E., Gold, R., Karami, M., Preciado-Lopez, J. A., Tiede, P., Pu, H. -Y., Akiyama, K., Alberdi, A., Alef, W., Asada, K., Azulay, R., Baczko, A. -K., Balokovic, M., Barrett, J., Bintley, D., Blackburn, L., Boland, W., Bouman, K. L., Bower, G. C., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broguiere, D., Bronzwaer, T., Byun, D. -Y., Carlstrom, J. E., Chael, A., Chatterjee, S., Chatterjee, K., Chen, M. -T., Chen, Y., Cho, I., Conway, J. E., Cordes, J. M., Crew, G. B., Cui, Y., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Doeleman, S. S., Eatough, R. P., Falcke, H., Fish, V. L., Fomalont, E., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Galison, P., Gammie, C. F., Garcia, R., Gentaz, O., Georgiev, B., Goddi, C., Gomez, J. L., Gu, M., Gurwell, M., Hada, K., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Inoue, M., Issaoun, S., James, D. J., Janssen, M., Jeter, B., Jiang, W., Jimenez-Rosales, A., Johnson, M. D., Jorstad, S., Jung, T., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, J. -Y., Kim, J., Kino, M., Koay, J. Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Krichbaum, T. P., Kuo, C. -Y., Lee, S. -S., Li, Y. -R., Li, Z., Lindqvist, M., Lico, R., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C., Lu, R. -S., Macdonald, N. R., Mao, J., Marscher, A. P., Marti-Vidal, I., Matsushita, S., Matthews, L. D., Menten, K. M., Mizuno, Y., Mizuno, I., Moran, J. M., Moriyama, K., Moscibrodzka, M., Muller, C., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Neri, R., Ni, C., Noutsos, A., Okino, H., Olivares, H., Ortiz-Leon, G. N., Oyama, T., Palumbo, D. C. M., Park, J., Pen, U. -L., Pesce, D. W., Pietu, V., Plambeck, R., Popstefanija, A., Porth, O., Prather, B., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Rottmann, H., Ruszczyk, C., Ryan, B. R., Rygl, K. L. J., Sanchez, S., Sanchez-Arguelles, D., Sasada, M., Savolainen, T., Schloerb, F. P., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Tazaki, F., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Traianou, E., Trippe, S., Tsuda, S., Van Bemmel, I., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhao, G., Zhao, S. -S., and Zhu, Z.

Subjects
010504 meteorology & atmospheric sciences, Exploit, Astronomy, 01 natural sciences, Data type, Set (abstract data type), Galactic center, 0103 physical sciences, Very-long-baseline interferometry, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Very long baseline interferometry, Physics, Event Horizon Telescope, Supermassive black hole, Astrophysical black holes, Galactic Center, Astronomy and Astrophysics, Black hole, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astronomy data analysis, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Algorithm, Submillimeter astronomy
Abstract

This is an open access article.-- Full list of authors: Broderick, Avery E.; Gold, Roman; Karami, Mansour; Preciado-López, Jorge A.; Tiede, Paul; Pu, Hung-Yi; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Asada, Keiichi; Azulay, Rebecca; Baczko, Anne-Kathrin; Baloković, Mislav; Barrett, John; Bintley, Dan; Blackburn, Lindy; Boland, Wilfred; Bouman, Katherine L.; Bower, Geoffrey C.; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broguiere, Dominique; Bronzwaer, Thomas; Byun, Do-Young; Carlstrom, John E.; Chael, Andrew; Chatterjee, Shami; Chatterjee, Koushik; Chen, Ming-Tang; Chen, Yongjun; Cho, Ilje; Conway, John E.; Cordes, James M.; Crew, Geoffrey B.; Cui, Yuzhu; Davelaar, Jordy; De Laurentis, Mariafelicia; Deane, Roger; Dempsey, Jessica; Desvignes, Gregory; Doeleman, Sheperd S.; Eatough, Ralph P.; Falcke, Heino; Fish, Vincent L.; Fomalont, Ed; Fraga-Encinas, Raquel; Friberg, Per; Fromm, Christian M.; Galison, Peter; Gammie, Charles F.; García, Roberto; Gentaz, Olivier; Georgiev, Boris; Goddi, Ciriaco; Gómez, José L.; Gu, Minfeng; Gurwell, Mark; Hada, Kazuhiro; Hecht, Michael H.; Hesper, Ronald; Ho, Luis C.; Ho, Paul; Honma, Mareki; Huang, Chih-Wei L.; Huang, Lei; Hughes, David H.; Inoue, Makoto; Issaoun, Sara; James, David J.; Janssen, Michael; Jeter, Britton; Jiang, Wu; Jiménez-Rosales, Alejandra; Johnson, Michael D.; Jorstad, Svetlana; Jung, Taehyun; Karuppusamy, Ramesh; Kawashima, Tomohisa; Keating, Garrett K.; Kettenis, Mark; Kim, Jae-Young; Kim, Jongsoo; Kino, Motoki; Koay, Jun Yi; Koch, Patrick M.; Koyama, Shoko; Kramer, Michael; Kramer, Carsten; Krichbaum, Thomas P.; Kuo, Cheng-Yu; Lee, Sang-Sung; Li, Yan-Rong; Li, Zhiyuan; Lindqvist, Michael; Lico, Rocco; Liu, Kuo; Liuzzo, Elisabetta; Lo, Wen-Ping; Lobanov, Andrei P.; Loinard, Laurent; Lonsdale, Colin; Lu, Ru-Sen; MacDonald, Nicholas R.; Mao, Jirong; Marscher, Alan P.; Martí-Vidal, Iván; Matsushita, Satoki; Matthews, Lynn D.; Menten, Karl M.; Mizuno, Yosuke; Mizuno, Izumi; Moran, James M.; Moriyama, Kotaro; Moscibrodzka, Monika; Müller, Cornelia; Nagai, Hiroshi; Nagar, Neil M.; Nakamura, Masanori; Narayan, Ramesh; Narayanan, Gopal; Natarajan, Iniyan; Neri, Roberto; Ni, Chunchong; Noutsos, Aristeidis; Okino, Hiroki; Olivares, Héctor; Ortiz-León, Gisela N.; Oyama, Tomoaki; Palumbo, Daniel C. M.; Park, Jongho; Pen, Ue-Li; Pesce, Dominic W.; Piétu, Vincent; Plambeck, Richard; PopStefanija, Aleksandar; Porth, Oliver; Prather, Ben; Ramakrishnan, Venkatessh; Rao, Ramprasad; Rawlings, Mark G.; Raymond, Alexander W.; Rezzolla, Luciano; Ripperda, Bart; Roelofs, Freek; Rogers, Alan; Ros, Eduardo; Rose, Mel; Rottmann, Helge; Ruszczyk, Chet; Ryan, Benjamin R.; Rygl, Kazi L. J.; Sánchez, Salvador; Sánchez-Arguelles, David; Sasada, Mahito; Savolainen, Tuomas; Schloerb, F. Peter; Schuster, Karl-Friedrich; Shao, Lijing; Shen, Zhiqiang; Small, Des; Sohn, Bong Won; SooHoo, Jason; Tazaki, Fumie; Tilanus, Remo P. J.; Titus, Michael; Toma, Kenji; Torne, Pablo; Traianou, Efthalia; Trippe, Sascha; Tsuda, Shuichiro; van Bemmel, Ilse; van Langevelde, Huib Jan; van Rossum, Daniel R.; Wagner, Jan; Wardle, John; Weintroub, Jonathan; Wex, Norbert; Wharton, Robert; Wielgus, Maciek; Wong, George N.; Wu, Qingwen; Yoon, Doosoo; Young, André; Young, Ken; Younsi, Ziri; Yuan, Feng; Yuan, Ye-Fei; Zensus, J. Anton; Zhao, Guangyao; Zhao, Shan-Shan; Zhu, Ziyan; Event Horizon Telescope Collaboration., The Event Horizon Telescope (EHT) provides the unprecedented ability to directly resolve the structure and dynamics of black hole emission regions on scales smaller than their horizons. This has the potential to critically probe the mechanisms by which black holes accrete and launch outflows, and the structure of supermassive black hole spacetimes. However, accessing this information is a formidable analysis challenge for two reasons. First, the EHT natively produces a variety of data types that encode information about the image structure in nontrivial ways; these are subject to a variety of systematic effects associated with very long baseline interferometry and are supplemented by a wide variety of auxiliary data on the primary EHT targets from decades of other observations. Second, models of the emission regions and their interaction with the black hole are complex, highly uncertain, and computationally expensive to construct. As a result, the scientific utilization of EHT observations requires a flexible, extensible, and powerful analysis framework. We present such a framework, Themis, which defines a set of interfaces between models, data, and sampling algorithms that facilitates future development. We describe the design and currently existing components of Themis, how Themis has been validated thus far, and present additional analyses made possible by Themis that illustrate its capabilities. Importantly, we demonstrate that Themis is able to reproduce prior EHT analyses, extend these, and do so in a computationally efficient manner that can efficiently exploit modern high-performance computing facilities. Themis has already been used extensively in the scientific analysis and interpretation of the first EHT observations of M87. © 2020. The Author(s). Published by the American Astronomical Society., This work was made possible by the facilities of the Shared Hierarchical Academic Research Computing Network (SHARCNET: www.sharcnet.ca) and Compute/Calcul Canada (www.computecanada.ca). Computations were made on the supercomputer Mammouth Parallele 2 from University of Sherbrooke, managed by Calcul Quebec and Compute Canada. The operation of this supercomputer is funded by the Canada Foundation for Innovation (CFI), the ministere de l'Economie, de la science et de l'innovation du Quebec (MESI), and the Fonds de recherche du Quebec-Nature et technologies (FRQ-NT). This work was supported in part by Perimeter Institute for Theoretical Physics. Research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development Canada and by the Province of Ontario through the Ministry of Economic Development, Job Creation and Trade. A.E.B. thanks the Delaney Family for their generous financial support via the Delaney Family John A. Wheeler Chair at Perimeter Institute. A.E.B., P.T., and M.K. receive additional financial support from the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant. R.G. receives additional support from the ERC synergy grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant No. 610058). We thank Jason Dexter for helpful comments and suggestions. We further thank the following organizations and programs: the Academy of Finland (projects 274477, 284495, 312496); the Advanced European Network of E-infrastructures for Astronomy with the SKA (AENEAS) project, supported by the European Commission Framework Programme Horizon 2020 Research and Innovation action under grant agreement 731016; the Alexander von Humboldt Stiftung; Black Hole Initiative at Harvard University, through grants from the John Templeton Foundation and the Gordon and Betty Moore Foundation; the China Scholarship Council; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT, Chile, via PIA ACT172033, Fondecyt 1171506, BASAL AFB-170002, ALMA-conicyt 31140007); Consejo Nacional de Ciencia y Tecnologia (CONACYT, Mexico, projects 104497, 275201, 279006, 281692); the Delaney Family via the Delaney Family John A. Wheeler Chair at Perimeter Institute; Direccion General de Asuntos del Personal Academico-Universidad Nacional Autonoma de Mexico (DGAPA-UNAM, project IN112417); the European Research Council Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (grant 610058); the Generalitat Valenciana postdoctoral grant APOSTD/2018/177; the Gordon and Betty Moore Foundation (grants GBMF-3561, GBMF-5278); the Istituto Nazionale di Fisica Nucleare (INFN) sezione di Napoli, iniziative specifiche TEONGRAV; the International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne; the Jansky Fellowship program of the National Radio Astronomy Observatory (NRAO); the Japanese Government (Monbukagakusho: MEXT) Scholarship; the Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for JSPS Research Fellowship (JP17J08829); the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS, grants QYZDJ-SSW-SLH057, QYZDJ-SSW-SYS008); the Leverhulme Trust Early Career Research Fellowship; the Max-Planck-Gesellschaft (MPG); the Max Planck Partner Group of the MPG and the CAS; the MEXT/JSPS KAKENHI (grants 18KK0090, JP18K13594, JP18K03656, JP18H03721, 18K03709, 18H01245, 25120007); the MIT International Science and Technology Initiatives (MISTI) Funds; the Ministry of Science and Technology (MOST) of Taiwan (105-2112-M-001-025-MY3, 106-2112-M-001-011, 106-2119-M-001-027, 107-2119-M-001-017, 107-2119-M-001-020, and 107-2119-M-110-005); the National Aeronautics and Space Administration (NASA, Fermi Guest Investigator grant 80NSSC17K0649); the National Institute of Natural Sciences (NINS) of Japan; the National Key Research and Development Program of China (grant 2016YFA0400704, 2016YFA0400702); the National Science Foundation (NSF, grants AST-0096454, AST-0352953, AST-0521233, AST-0705062, AST-0905844, AST-0922984, AST-1126433, AST-1140030, DGE-1144085, AST-1207704, AST-1207730, AST-1207752, MRI-1228509, OPP-1248097, AST-1310896, AST-1337663, AST-1440254, AST-1555365, AST-1715061, AST-1615796, AST-1716327, OISE-1743747, AST-1816420); the Natural Science Foundation of China (grants 11573051, 11633006, 11650110427, 10625314, 11721303, 11725312); the Natural Sciences and Engineering Research Council of Canada (NSERC, including a Discovery Grant and the NSERC Alexander Graham Bell Canada Graduate Scholarships-Doctoral Program); the National Youth Thousand Talents Program of China; the National Research Foundation of Korea (the Global PhD Fellowship Grant: grants NRF-2015H1A2A1033752, 2015-R1D1A1A01056807, the Korea Research Fellowship Program: NRF-2015H1D3A1066561); the Netherlands Organization for Scientific Research (NWO) VICI award (grant 639.043. 513) and Spinoza Prize SPI 78-409; the New Scientific Frontiers with Precision Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Technology (DST) of South Africa; the Onsala Space Observatory (OSO) national infrastructure, for the provisioning of its facilities/observational support (OSO receives funding through the Swedish Research Council under grant 2017-00648) the Perimeter Institute for Theoretical Physics (research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development and by the Province of Ontario through the Ministry of Research, Innovation and Science); the Russian Science Foundation (grant 17-12-01029); the Spanish Ministerio de Economia y Competitividad (grants PGC2018-098915-B-C21, AYA2016-80889-P); the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709); the Toray Science Foundation; the US Department of Energy (USDOE) through the Los Alamos National Laboratory (operated by Triad National Security, LLC, for the National Nuclear Security Administration of the USDOE (Contract 89233218CNA000001)); the Italian Ministero dell'Istruzione Universita e Ricerca through the grant Progetti Premiali 2012-iALMA (CUP C52I13000140001); the European Union's Horizon 2020 research and innovation program under grant agreement No. 730562 RadioNet; ALMA North America Development Fund; the Academia Sinica; Chandra TM6-17006X. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant ACI-1548562, and CyVerse, supported by NSF grants DBI-0735191, DBI-1265383, and DBI-1743442. XSEDE Stampede2 resource at TACC was allocated through TG-AST170024 and TG-AST080026N. XSEDE JetStream resource at PTI and TACC was allocated through AST170028. The simulations were performed in part on the SuperMUC cluster at the LRZ in Garching, on the LOEWE cluster in CSC in Frankfurt, and on the HazelHen cluster at the HLRS in Stuttgart.

Published
2020

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