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1. First Very Long Baseline Interferometry Detections at 870{\mu}m

Author: Raymond, Alexander W., Doeleman, Sheperd S., Asada, Keiichi, Blackburn, Lindy, Bower, Geoffrey C., Bremer, Michael, Broguiere, Dominique, Chen, Ming-Tang, Crew, Geoffrey B., Dornbusch, Sven, Fish, Vincent L., García, Roberto, Gentaz, Olivier, Goddi, Ciriaco, Han, Chih-Chiang, Hecht, Michael H., Huang, Yau-De, Janssen, Michael, Keating, Garrett K., Koay, Jun Yi, Krichbaum, Thomas P., Lo, Wen-Ping, Matsushita, Satoki, Matthews, Lynn D., Moran, James M., Norton, Timothy J., Patel, Nimesh, Pesce, Dominic W., Ramakrishnan, Venkatessh, Rottmann, Helge, Roy, Alan L., Sánchez, Salvador, Tilanus, Remo P. J., Titus, Michael, Torne, Pablo, Wagner, Jan, Weintroub, Jonathan, Wielgus, Maciek, Young, André, Akiyama, Kazunori, Albentosa-Ruíz, Ezequiel, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Azulay, Rebecca, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Baloković, Mislav, Bandyopadhyay, Bidisha, Barrett, John, Bauböck, Michi, Benson, Bradford A., Bintley, Dan, Blundell, Raymond, Bouman, Katherine L., Boyce, Hope, Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Bronzwaer, Thomas, Bustamante, Sandra, Carlstrom, John E., Chael, Andrew, Chan, Chi-kwan, Chang, Dominic O., Chatterjee, Koushik, Chatterjee, Shami, Chen, Yongjun, Cheng, Xiaopeng, Cho, Ilje, Christian, Pierre, Conroy, Nicholas S., Conway, John E., Crawford, Thomas M., Cruz-Osorio, Alejandro, Cui, Yuzhu, Dahale, Rohan, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Dhruv, Vedant, Dihingia, Indu K., Dzib, Sergio A., Eatough, Ralph P., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fomalont, Edward, Fontana, Anne-Laure, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, Gammie, Charles F., Georgiev, Boris, Gold, Roman, Gómez-Ruiz, Arturo I., Gómez, José L., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, 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., Jeter, Britton, Jiang, Wu, Jiménez-Rosales, Alejandra, Johnson, Michael D., Jorstad, Svetlana, Jones, Adam C., Joshi, Abhishek V., Jung, Taehyun, Karuppusamy, Ramesh, Kawashima, Tomohisa, Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Kocherlakota, Prashant, Kofuji, Yutaro, Koch, Patrick M., Koyama, Shoko, Kramer, Carsten, Kramer, Joana A., Kramer, Michael, Kubo, Derek, Kuo, Cheng-Yu, La Bella, Noemi, Lee, Sang-Sung, Levis, Aviad, Li, Zhiyuan, Lico, Rocco, Lindahl, Greg, Lindqvist, Michael, Lisakov, Mikhail, Liu, Jun, Liu, Kuo, Liuzzo, Elisabetta, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin J., Lowitz, Amy E., Lu, Ru-Sen, MacDonald, Nicholas R., Mahieu, Sylvain, Maier, Doris, Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Martí-Vidal, Iván, Medeiros, Lia, Menten, Karl M., Mizuno, Izumi, Mizuno, Yosuke, Montgomery, Joshua, Moriyama, Kotaro, Moscibrodzka, Monika, Mulaudzi, Wanga, Müller, Cornelia, Müller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Fuentes, Santiago Navarro, Neilsen, Joey, Ni, Chunchong, Nowak, Michael A., Oh, Junghwan, Okino, Hiroki, Sánchez, Héctor Raúl Olivares, Oyama, Tomoaki, Özel, Feryal, Palumbo, Daniel C. M., Paraschos, Georgios Filippos, Park, Jongho, Parsons, Harriet, Pen, Ue-Li, Piétu, Vincent, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Principe, Giacomo, Psaltis, Dimitrios, Pu, Hung-Yi, Raffin, Philippe A., Rao, Ramprasad, Rawlings, Mark G., Ricarte, Angelo, Ripperda, Bart, Roelofs, Freek, Romero-Cañizales, Cristina, Ros, Eduardo, Roshanineshat, Arash, Ruiz, Ignacio, Ruszczyk, Chet, Rygl, Kazi L. J., 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, Salas, León David Sosapanta, Souccar, Kamal, Srinivasan, Ranjani, Stanway, Joshua S., Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Toma, Kenji, Toscano, Teresa, Traianou, Efthalia, Trent, Tyler, Trippe, Sascha, Turk, Matthew, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Vos, Jesse, Ward-Thompson, Derek, Wardle, John, Washington, Jasmin E., Wharton, Robert, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Younsi, Ziri, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The first very long baseline interferometry (VLBI) detections at 870$\mu$m wavelength (345$\,$GHz frequency) are reported, achieving the highest diffraction-limited angular resolution yet obtained from the surface of the Earth, and the highest-frequency example of the VLBI technique to date. These include strong detections for multiple sources observed on inter-continental baselines between telescopes in Chile, Hawaii, and Spain, obtained during observations in October 2018. The longest-baseline detections approach 11$\,$G$\lambda$ corresponding to an angular resolution, or fringe spacing, of 19$\mu$as. The Allan deviation of the visibility phase at 870$\mu$m is comparable to that at 1.3$\,$mm on the relevant integration time scales between 2 and 100$\,$s. The detections confirm that the sensitivity and signal chain stability of stations in the Event Horizon Telescope (EHT) array are suitable for VLBI observations at 870$\mu$m. Operation at this short wavelength, combined with anticipated enhancements of the EHT, will lead to a unique high angular resolution instrument for black hole studies, capable of resolving the event horizons of supermassive black holes in both space and time., Comment: Corresponding author: S. Doeleman
Published: 2024
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2. The Near-Ultraviolet eXplorer (NUX): a ground-based wide-field near-UV telescope to search for near-UV transients

Author: Wijnands, Rudy, Bloemen, Steven, Sloot, Rasjied, ter Horst, Rik, Young, Andre, Bakker, Mattijs, Groot, Paul, and Vreeswijk, Paul
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: We present the Near-Ultraviolet eXplorer (NUX), which will consist out of 4 small (36 cm diameter) ground-based telescopes that are optimized for the shortest wavelengths that are detectable from Earth (i.e., the near-UV [NUV] wavelength range of 300-350 nm). Each telescope will have a field-of-view of ~17 square degrees sampled at ~2.6"/pixel, and will reach a NUV magnitude (AB) of 20 in 2.5 minutes exposures (in dark time). The goal of NUX is to improve our understanding of the physical processes that power fast (days) to very fast (hours) hot transients, such as shock-breakout and shock-cooling emission of supernovae and the electromagnetic counterparts of gravitational wave events. Each telescope will be an off-the-shelf 14" Celestron RASA telescope, retrofitted with NUV optics. We have already demonstrated that the normal Schmidt corrector of this telescope can be replaced by a custom made one consisting of NUV transparent glass. Currently, a prototype NUX telescope is being fully assembled to demonstrate the technical and scientific feasibility of the NUX concept. Site tests will be held (in 2025/2026) at La Silla, Chile, to determine the NUV characteristics of the atmosphere at this site., Comment: Published in Proc. SPIE 13094, Ground-based and Airborne Telescopes X, 1309430 (11 September 2024)
Published: 2024
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3. A search for pulsars around Sgr A* in the first Event Horizon Telescope dataset

Author: Torne, Pablo, Liu, Kuo, Eatough, Ralph P., Wongphechauxsorn, Jompoj, Cordes, James M., Desvignes, Gregory, De Laurentis, Mariafelicia, Kramer, Michael, Ransom, Scott M., Chatterjee, Shami, Wharton, Robert, Karuppusamy, Ramesh, Blackburn, Lindy, Janssen, Michael, Chan, Chi-kwan, Crew, Geoffrey B., Matthews, Lynn D., Goddi, Ciriaco, Rottmann, Helge, Wagner, Jan, Sanchez, Salvador, Ruiz, Ignacio, Abbate, Federico, Bower, Geoffrey C., Salamanca, Juan J., Gomez-Ruiz, Arturo I., Herrera-Aguilar, Alfredo, Jiang, Wu, Lu, Ru-Sen, Pen, Ue-Li, Raymond, Alexander W., Shao, Lijing, Shen, Zhiqiang, Paubert, Gabriel, Sanchez-Portal, Miguel, Kramer, Carsten, Castillo, Manuel, Navarro, Santiago, John, David, Schuster, Karl-Friedrich, Johnson, Michael D., Rygl, Kazi L. J., 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, Bauboeck, Michi, Benson, Bradford A., Bintley, Dan, Blundell, Raymond, Bouman, Katherine L., 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, Chang, Dominic O., Chatterjee, Koushik, Chen, Ming-Tang, Chen, Yongjun, Cheng, Xiaopeng, Cho, Ilje, Christian, Pierre, Conroy, Nicholas S., Conway, John E., Crawford, Thomas M., Cruz-Osorio, Alejandro, Cui, Yuzhu, Dahale, Rohan, Davelaar, Jordy, Deane, Roger, Dempsey, Jessica, Dexter, Jason, Dhruv, Vedant, Doeleman, Sheperd S., Dougal, Sean, Dzib, Sergio A., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Gold, Roman, 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., Jeter, Britton, Jimenez-Rosales, Alejandra, Jorstad, Svetlana, Joshi, Abhishek V., Jung, Taehyun, Karami, Mansour, 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, Koyama, Shoko, 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, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin J., MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Medeiros, Lia, Menten, Karl M., Michalik, Daniel, Mizuno, Izumi, Mizuno, Yosuke, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Muller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, 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., 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, 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., Rezzolla, Luciano, Ricarte, Angelo, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, Ros, Eduardo, Romero-Cañizales, Cristina, Roshanineshat, Arash, Roy, Alan L., Ruszczyk, Chet, Sanchez-Arguelles, David, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfeld, Jonathan, Small, Des, Sohn, Bong Won, SooHoo, Jason, Souccar, Kamal, Sun, He, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toscano, Teresa, Traianou, Efthalia, Trent, Tyler, Trippe, Sascha, Turk, Matthew, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Vos, Jesse, Ward-Thompson, Derek, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wielgus, Maciek, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, Andre, Young, Ken, Younsi, Ziri, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Event Horizon Telescope (EHT) observed in 2017 the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), at a frequency of 228.1 GHz ($\lambda$=1.3 mm). The fundamental physics tests that even a single pulsar orbiting Sgr A* would enable motivate searching for pulsars in EHT datasets. The high observing frequency means that pulsars - which typically exhibit steep emission spectra - are expected to be very faint. However, it also negates pulse scattering, an effect that could hinder pulsar detections in the Galactic Center. Additionally, magnetars or a secondary inverse Compton emission could be stronger at millimeter wavelengths than at lower frequencies. We present a search for pulsars close to Sgr A* using the data from the three most-sensitive stations in the EHT 2017 campaign: the Atacama Large Millimeter/submillimeter Array, the Large Millimeter Telescope and the IRAM 30 m Telescope. We apply three detection methods based on Fourier-domain analysis, the Fast-Folding-Algorithm and single pulse search targeting both pulsars and burst-like transient emission; using the simultaneity of the observations to confirm potential candidates. No new pulsars or significant bursts were found. Being the first pulsar search ever carried out at such high radio frequencies, we detail our analysis methods and give a detailed estimation of the sensitivity of the search. We conclude that the EHT 2017 observations are only sensitive to a small fraction ($\lesssim$2.2%) of the pulsars that may exist close to Sgr A*, motivating further searches for fainter pulsars in the region., Comment: 33 pages, 7 figures, 6 Tables. Accepted for publication in ApJ
Published: 2023

4. Comparison of Polarized Radiative Transfer Codes used by the EHT Collaboration

Author: Prather, Ben S., Dexter, Jason, Moscibrodzka, Monika, Pu, Hung-Yi, Bronzwaer, Thomas, Davelaar, Jordy, Younsi, Ziri, Gammie, Charles F., Gold, Roman, Wong, George N., Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, 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, Broderick, Avery E., Broguiere, Dominique, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E., Ceccobello, Chiara, Chael, Andrew, Chan, Chi-kwan, Chang, Dominic O., 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, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, 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, García, Roberto, Gentaz, Olivier, Georgiev, Boris, 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, 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, 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, MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Martí-Vidal, Iván, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Michalik, Daniel, Mizuno, Izumi, Mizuno, Yosuke, Moran, James M., Moriyama, Kotaro, Müller, 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, Héctor, Ortiz-León, Gisela N., Oyama, Tomoaki, Özel, Feryal, Palumbo, Daniel C. M., Paraschos, Georgios Filippos, Park, Jongho, Parsons, Harriet, Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Piétu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Pötzl, Felix M., Preciado-López, Jorge A., Psaltis, Dimitrios, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Raymond, Alexander W., Rezzolla, Luciano, Ricarte, Angelo, 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., Vos, Jesse, Wagner, Jan, Ward-Thompson, Derek, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wielgus, Maciek, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wu, Qingwen, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, André, Young, Ken, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Interpretation of resolved polarized images of black holes by the Event Horizon Telescope (EHT) requires predictions of the polarized emission observable by an Earth-based instrument for a particular model of the black hole accretion system. Such predictions are generated by general relativistic radiative transfer (GRRT) codes, which integrate the equations of polarized radiative transfer in curved spacetime. A selection of ray-tracing GRRT codes used within the EHT collaboration is evaluated for accuracy and consistency in producing a selection of test images, demonstrating that the various methods and implementations of radiative transfer calculations are highly consistent. When imaging an analytic accretion model, we find that all codes produce images similar within a pixel-wise normalized mean squared error (NMSE) of 0.012 in the worst case. When imaging a snapshot from a cell-based magnetohydrodynamic simulation, we find all test images to be similar within NMSEs of 0.02, 0.04, 0.04, and 0.12 in Stokes I, Q, U , and V respectively. We additionally find the values of several image metrics relevant to published EHT results to be in agreement to much better precision than measurement uncertainties., Comment: Accepted for publication in ApJ
Published: 2023
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5. Process simulation and economic evaluation of the Alcohol-to-Jet production of sustainable aviation fuel in the Brazilian context

Author: Teixeira, Adryena T., da Silva, Amanda C.M., Cavalcante, Raquel M., and Young, André F.
Published: 2024
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6. Process simulation and economic evaluation of the industrial production of triacetin from glycerol: Comparing acetic acid and acetic anhydride as possible reagents

Author: dos Santos, Heitor C., Stutz, Beatriz E., and Young, André F.
Published: 2024
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7. Event Horizon Telescope observations of the jet launching and collimation in Centaurus A

Author: Janssen, Michael, Falcke, Heino, Kadler, Matthias, Ros, Eduardo, Wielgus, Maciek, Akiyama, Kazunori, Baloković, Mislav, Blackburn, Lindy, Bouman, Katherine L., Chael, Andrew, Chan, Chi-kwan, Chatterjee, Koushik, Davelaar, Jordy, Edwards, Philip G., Fromm, Christian M., Gómez, José L., Goddi, Ciriaco, Issaoun, Sara, Johnson, Michael D., Kim, Junhan, Koay, Jun Yi, Krichbaum, Thomas P., Liu, Jun, Liuzzo, Elisabetta, Markoff, Sera, Markowitz, Alex, Marrone, Daniel P., Mizuno, Yosuke, Müller, Cornelia, Ni, Chunchong, Pesce, Dominic W., Ramakrishnan, Venkatessh, Roelofs, Freek, Rygl, Kazi L. J., van Bemmel, Ilse, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Barrett, John, Benson, Bradford A., Bintley, Dan, Blundell, Raymond, Boland, Wilfred, 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., Chatterjee, Shami, 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, Cui, Yuzhu, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph P., Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Ford, H. Alyson, Fraga-Encinas, Raquel, Friberg, Per, Fuentes, Antonio, Galison, Peter, Gammie, Charles F., García, Roberto, Gelles, Zachary, Gentaz, Olivier, Georgiev, Boris, Gold, Roman, Gómez-Ruiz, Arturo I., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Hecht, Michael H., Hesper, Ronald, Himwich, Elizabeth, Ho, Luis C., Ho, Paul, Honma, Mareki, Huang, Chih-Wei L., Huang, Lei, Hughes, David H., Ikeda, Shiro, Inoue, Makoto, James, David J., Jannuzi, Buell T., 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, Kino, Motoki, Kofuji, Yutaro, Koyama, Shoko, Kramer, Michael, Kramer, Carsten, Kuo, Cheng-Yu, Lauer, Tod R., Lee, Sang-Sung, Levis, Aviad, Li, Yan-Rong, Li, Zhiyuan, Lindqvist, Michael, Lico, Rocco, Lindahl, Greg, Liu, Kuo, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin, Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Marscher, Alan P., Martí-Vidal, Iván, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Musoke, Gibwa, Mejías, Alejandro Mus, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Neilsen, Joey, Neri, Roberto, Noutsos, Aristeidis, Nowak, Michael A., Okino, Hiroki, Olivares, Héctor, Ortiz-León, Gisela N., Oyama, Tomoaki, Özel, 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, Rao, Ramprasad, Rawlings, Mark G., Raymond, Alexander W., Rezzolla, Luciano, Ricarte, Angelo, Ripperda, Bart, Rogers, Alan, Rose, Mel, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L., Ruszczyk, Chet, 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, Torne, Pablo, Trent, Tyler, Traianou, Efthalia, Trippe, Sascha, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Ward-Thompson, Derek, Wardle, John, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wong, George N., Wu, Qingwen, Yoon, Doosoo, Young, André, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guang-Yao, and Zhao, Shan-Shan
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimeter wavelengths have the power to reveal the launching and initial collimation region of extragalactic radio jets, down to $10-100$ gravitational radii ($r_g=GM/c^2$) scales in nearby sources. Centaurus A is the closest radio-loud source to Earth. It bridges the gap in mass and accretion rate between the supermassive black holes (SMBHs) in Messier 87 and our galactic center. A large southern declination of $-43^{\circ}$ has however prevented VLBI imaging of Centaurus A below ${\lambda}1$cm thus far. Here, we show the millimeter VLBI image of the source, which we obtained with the Event Horizon Telescope at $228$GHz. Compared to previous observations, we image Centaurus A's jet 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 Centaurus A's source structure resembles the jet in Messier 87 on ${\sim}500r_g$ scales remarkably well. Furthermore, we identify the location of Centaurus A's SMBH with respect to its resolved jet core at ${\lambda}1.3$mm and conclude that the source's event horizon shadow should be visible at THz frequencies. This location further supports the universal scale invariance of black holes over a wide range of masses., Comment: 27 pages, 9 figures. This is a post-peer-review, pre-copyedit version of an article published in Nature Astronomy. The final authenticated version is available online at: https://doi.org/10.1038/s41550-021-01417-w
Published: 2021
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8. The Variability of the Black-Hole Image in M87 at the Dynamical Time Scale

Author: Satapathy, Kaushik, Psaltis, Dimitrios, Ozel, 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 R., Baloković, Mislav, Barrett, John, Benson, Bradford A., Bintley, Dan, Blackburn, Lindy, Blundell, Raymond, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., Boyce, Hope A., 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, Crew, Geoffrey B., Osorio, Alejandro Cruz, Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica T., Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph, Falcke, Heino, Farah, Joseph R., Fish, Vincent, Fomalont, Edward B., 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, Gomez-Ruiz, Arturo I., Gómez, Jose L., Gu, Minfeng, Gurwell, Mark A., Hada, Kazuhiro, Haggard, Daryl, Hecht, Michael, Hesper, Ronald, Ho, Luis C., Ho, Paul T., 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, Rosales, Alejandra Jimenez, Johnson, Michael D., Jorstad, Svetlana G., 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, Miss Elisabetta, Lo, Wen-Ping, Lobanov, Andrei, Loinard, Laurent, Lonsdale, Colin J., Lu, Rusen, MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel, Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn, Menten, Karl M., Mizuno, Izumi, Mizuno, Yosuke, Moran, James, Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Mejias, Alejandro M., 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, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Palumbo, Daniel C., Park, Jongho, Patel, Nimesh A., Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard L., PopStefanija, Aleksandar, Porth, Oliver, Potzl, Felix, Preciado-López, Jorge A., Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark, Raymond, Alexander W., Rezzolla, Luciano, Ripperda, Bart, Roelofs, Freek, Rogers, Alan E. E., Ros, Eduardo, Rose, Mel, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L., Ruszczyk, Chet, Rygl, Kazi, Sanchez, Salvador, Sanchez-Arguelles, David, Sasada, Mahito, Savolainen, Tuomas, Schloerb, F Peter, Schuster, Karl-Friedrich, Shao, Lijing, Shen, Zhi-Qiang, Small, Des, Sohn, Bong Won, SooHoo, Jason, Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo, Titus, Michael, Toma, Kenji, Torne, Pablo, Traianou, E., Trent, Tyler, Trippe, Sascha, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Ward-Thompson, Derek, Wardle, John F., Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wiik, Kaj, Wu, Qingwen, Yoon, DooSoo, Young, Andre, Young, Ken H., Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guang-Yao, and Zhao, Shan-Shan
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: 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 non-trivial 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 $\sim3-5^\circ$. The only triangles that exhibit substantially higher variability ($\sim90-180^\circ$) are the ones with baselines that cross 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., Comment: Accepted for Publication in ApJ
Published: 2021
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9. Constraints on black-hole charges with the 2017 EHT observations of M87*

Author: Kocherlakota, Prashant, Rezzolla, Luciano, Falcke, Heino, Fromm, Christian M., Kramer, Michael, Mizuno, Yosuke, Nathanail, Antonios, Olivares, Hector, Younsi, Ziri, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, 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, 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, Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Doeleman, Sheperd S., Eatough, Ralph P., Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Fraga-Encinas, Raquel, Friberg, Per, Ford, H. Alyson, Fuentes, Antonio, Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, Gomez, Jose L., Gomez-Ruiz, Arturo I., 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, 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., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Musoke, Gibwa, Mejias, Alejandro Mus, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neilsen, Joseph, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A., Okino, Hiroki, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Park, Jongho, 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., 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., Sanchez, Salvador, Sanchez-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, 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, Andre, Young, Ken, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guang-Yao, Zhao, Shan-Shan, and Collaboration, The EHT
Subjects: General Relativity and Quantum Cosmology
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., Comment: 15 pages, 4 figures, published in PRD on May 19
Published: 2021
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10. The Polarized Image of a Synchrotron Emitting Ring of Gas Orbiting a Black Hole

Author: Narayan, Ramesh, Palumbo, Daniel C. M., Johnson, Michael D., Gelles, Zachary, Himwich, Elizabeth, Chang, Dominic O., Ricarte, Angelo, Dexter, Jason, Gammie, Charles F., Chael, Andrew A., Collaboration, The Event Horizon Telescope, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, 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, Byun, Do-Young, Carlstrom, John E., 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, Cui, Yuzhu, Davelaar, Jordy, DeLaurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, 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, Garcıa, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, Gomez, Jose L., Gomez-Ruiz, Arturo I., 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, 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, Michael, Kramer, Carsten, 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-Pin, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin, Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel P., Martı-Vidal, Alan P. Marscher Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Izumi, Mizuno, Yosuke, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Musoke, Gibwa, Mejıas, Alejandro Mus, 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, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Park, Jongho, 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, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, Ros, Eduardo, Rose, Mel, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L., Ruszczyk, Chet, Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-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, 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, Andre, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guang-Yao, and Zhao, Shan-Shan
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is determined by effects including the orientation of the magnetic field in the emitting region, relativistic motion of the gas, strong gravitational lensing by the black hole, and parallel transport in the curved spacetime. We explore these effects using a simple model of an axisymmetric, equatorial accretion disk around a Schwarzschild black hole. By using an approximate expression for the null geodesics derived by Beloborodov (2002) and conservation of the Walker-Penrose constant, we provide analytic estimates for the image polarization. We test this model using currently favored general relativistic magnetohydrodynamic simulations of M87*, using ring parameters given by the simulations. For a subset of these with modest Faraday effects, we show that the ring model broadly reproduces the polarimetric image morphology. Our model also predicts the polarization evolution for compact flaring regions, such as those observed from Sgr A* with GRAVITY. With suitably chosen parameters, our simple model can reproduce the EVPA pattern and relative polarized intensity in Event Horizon Telescope images of M87*. Under the physically motivated assumption that the magnetic field trails the fluid velocity, this comparison is consistent with the clockwise rotation inferred from total intensity images., Comment: 29 pages, 11 figures, published in ApJ on May 3
Published: 2021
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11. Gravitational Test Beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole

Author: Psaltis, Dimitrios, Medeiros, Lia, Christian, Pierre, Ozel, Feryal, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Ball, David, Balokovic, 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, Gomez, Jose 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, Ivan, Matsushita, Satoki, Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Musoke, Gibwa, Mejías, Alejandro Mus, Nagai, Hiroshi, Nagar, Neil M., Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Oyama, Tomoaki, Palumbo, Daniel C. M., Park, Jongho, Patel, Nimesh, Pen, Ue-Li, Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Prather, Ben, Preciado-Lopez, 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., Sanchez, Salvador, Sanchez-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, Andre, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zhao, Shan-Shan, and Collaboration, the EHT
Subjects: General Relativity and Quantum Cosmology, Astrophysics - High Energy Astrophysical Phenomena
Abstract: 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., Comment: Physical Review Letters
Published: 2020
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12. Industrial production of green diesel in Brazil: Process simulation and economic perspectives

Author: Barbosa, Ian V., Scapim, Letícia A., Cavalcante, Raquel M., and Young, André F.
Published: 2023
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13. Detection of pulses from the Vela pulsar at millimeter wavelengths with phased ALMA

Author: Liu, Kuo, Young, Andre, Wharton, Robert, Blackburn, Lindy, Cappallo, Roger, Chatterjee, Shami, Cordes, James M., Crew, Geoffrey B., Desvignes, Gregory, Doeleman, Sheperd S., Eatough, Ralph P., Falcke, Heino, Goddi, Ciriaco, Johnson, Michael D., Johnston, Simon, Karuppusamy, Ramesh, Kramer, Michael, Matthews, Lynn D., Ransom, Scott M., Rezzolla, Luciano, Rottmann, Helge, Tilanus, Remo P. J., and Torne, Pablo
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: We report on the first detection of pulsed radio emission from a radio pulsar with the ALMA telescope. The detection was made in the Band-3 frequency range (85-101 GHz) using ALMA in the phased-array mode developed for VLBI observations. A software pipeline has been implemented to enable a regular pulsar observing mode in the future. We describe the pipeline and demonstrate the capability of ALMA to perform pulsar timing and searching. We also measure the flux density and polarization properties of the Vela pulsar (PSR J0835$-$4510) at mm-wavelengths, providing the first polarimetric study of any ordinary pulsar at frequencies above 32 GHz. Finally, we discuss the lessons learned from the Vela observations for future pulsar studies with ALMA, particularly for searches near the supermassive black hole in the Galactic Center, and the potential of using pulsars for polarization calibration of ALMA., Comment: 8 pages, 6 figures, published in ApJ letter
Published: 2019
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14. Process simulation and economic evaluation of an integrated production plant for methanol, acetic acid and DME synthesis via sugarcane bagasse gasification

Author: P. C. Moura, Caio, de Araujo Filho, Marcos A., G. D. Villardi, Hugo, Cavalcante, Raquel M., and Young, André F.
Published: 2023
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15. Simulation and economic evaluation of a multipurpose pyrolysis plant for bio-oil production from different residual biomasses in Brazil

Author: Bittencourt, Fabio P. and Young, André F.
Published: 2023
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16. Experimental methodology for CO2 capture and sodium bicarbonate synthesis with producedwater from oil industry

Author: Villardi, Hugo Gomes D’Amato, Yokoyama, Lidia, Young, Andre, Veiga, Andrea Azevedo, and Pagnin, Sergio
Published: 2022
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17. Process simulation for technical and economic evaluation of acrolein and glycerol carbonate production from glycerol

Author: Guedes, Pedro Henrique P.S., Luz, Rinaldo F., Cavalcante, Raquel M., and Young, André F.
Published: 2023
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18. A VLBI receiving system for the South Pole Telescope

Author: Kim, Junhan, Marrone, Daniel P., Beaudoin, Christopher, Carlstrom, John E., Doeleman, Sheperd S., Folkers, Thomas W., Forbes, David, Greer, Christopher H., Lauria, Eugene F., Massingill, Kyle D., Mayer, Evan, Nguyen, Chi H., Reiland, George, SooHoo, Jason, Stark, Antony A., Vertatschitsch, Laura, Weintroub, Jonathan, and Young, André
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Event Horizon Telescope (EHT) is a very-long-baseline interferometry (VLBI) experiment that aims to observe supermassive black holes with an angular resolution that is comparable to the event horizon scale. The South Pole occupies an important position in the array, greatly increasing its north-south extent and therefore its resolution. The South Pole Telescope (SPT) is a 10-meter diameter, millimeter-wavelength telescope equipped for bolometric observations of the cosmic microwave background. To enable VLBI observations with the SPT we have constructed a coherent signal chain suitable for the South Pole environment. The dual-frequency receiver incorporates state-of-the-art SIS mixers and is installed in the SPT receiver cabin. The VLBI signal chain also includes a recording system and reference frequency generator tied to a hydrogen maser. Here we describe the SPT VLBI system design in detail and present both the lab measurements and on-sky results., Comment: 14 pages, 11 figures, to appear in the Proceedings of the SPIE (SPIE Astronomical Telescopes + Instrumentation 2018; Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX)
Published: 2018

19. Simulation and economic evaluation of different process alternatives for the fermentation and distillation steps of ethanol production

Author: Thielmann, Erika, Cavalcante, Raquel M., and Young, André F.
Published: 2022
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20. Biodiesel production through non-conventional supercritical routes: Economic evaluation

Author: Pacheco, João R., Villardi, Hugo G.D., Cavalcante, Raquel M., and Young, André F.
Published: 2022
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21. Determining the neutrino mass with Cyclotron Radiation Emission Spectroscopy - Project 8

Author: Esfahani, Ali Ashtari, Asner, David M., Böser, Sebastian, Cervantes, Raphael, Claessens, Christine, de Viveiros, Luiz, Doe, Peter J., Doeleman, Shepard, Fernandes, Justin L., Fertl, Martin, Finn, Erin C., Formaggio, Joseph A., Furse, Daniel, Guigue, Mathieu, Heeger, Karsten M., Jones, A. Mark, Kazkaz, Kareem, Kofron, Jared A., Lamb, Callum, LaRoque, Benjamin H., Machado, Eric, McBride, Elizabeth L., Miller, Michael L., Monreal, Benjamin, Mohanmurthy, Prajwal, Nikkel, James A., Oblath, Noah S., Pettus, Walter C., Robertson, R. G. Hamish, Rosenberg, Leslie J., Rybka, Gray, Rysewyk, Devyn, Saldaña, Luis, Slocum, Penny L., Sternberg, Matthew G., Tedeschi, Jonathan R., Thümmler, Thomas, VanDevender, Brent A., Vertatschitsch, Laura E., Wachtendonk, Megan, Weintroub, Jonathan, Woods, Natasha L., Young, André, and Zayas, Evan M.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract: The most sensitive direct method to establish the absolute neutrino mass is observation of the endpoint of the tritium beta-decay spectrum. Cyclotron Radiation Emission Spectroscopy (CRES) is a precision spectrographic technique that can probe much of the unexplored neutrino mass range with $\mathcal{O}({\rm eV})$ resolution. A lower bound of $m(\nu_e) \gtrsim 9(0.1)\, {\rm meV}$ is set by observations of neutrino oscillations, while the KATRIN Experiment - the current-generation tritium beta-decay experiment that is based on Magnetic Adiabatic Collimation with an Electrostatic (MAC-E) filter - will achieve a sensitivity of $m(\nu_e) \lesssim 0.2\,{\rm eV}$. The CRES technique aims to avoid the difficulties in scaling up a MAC-E filter-based experiment to achieve a lower mass sensitivity. In this paper we review the current status of the CRES technique and describe Project 8, a phased absolute neutrino mass experiment that has the potential to reach sensitivities down to $m(\nu_e) \lesssim 40\,{\rm meV}$ using an atomic tritium source., Comment: 19 pages, 8 figures, to be published in Journal of Physics G
Published: 2017
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22. Biodiesel production through non-conventional supercritical routes: Process simulation and technical evaluation

Author: Pacheco, João R., Villardi, Hugo G.D., Cavalcante, Raquel M., and Young, André F.
Published: 2022
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23. SWARM: A 32 GHz Correlator and VLBI Beamformer for the Submillimeter Array

Author: Primiani, Rurik A., Young, Kenneth H., Young, André, Patel, Nimesh, Wilson, Robert W., Vertatschitsch, Laura, Chitwood, Billie B., Srinivasan, Ranjani, MacMahon, David, and Weintroub, Jonathan
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: A 32 GHz bandwidth VLBI capable correlator and phased array has been designed and deployed at the Smithsonian Astrophysical Observatory's Submillimeter Array (SMA). The SMA Wideband Astronomical ROACH2 Machine (SWARM) integrates two instruments: a correlator with 140 kHz spectral resolution across its full 32 GHz band, used for connected interferometric observations, and a phased array summer used when the SMA participates as a station in the Event Horizon Telescope (EHT) Very Long Baseline Interferometry (VLBI) array. For each SWARM quadrant, Reconfigurable Open Architecture Computing Hardware (ROACH2) units shared under open source from the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) are equipped with a pair of ultra-fast Analog-to- Digital Converters (ADCs), a Field Programmable Gate Array (FPGA) processor, and eight 10 Gigabit Ethernet ports. A VLBI data recorder interface designated the SWARM Digital Back End, or SDBE, is implemented with a ninth ROACH2 per quadrant, feeding four Mark6 VLBI recorders with an aggregate recording rate of 64 Gbps. This paper describes the design and implementation of SWARM, as well as its deployment at SMA with reference to verification and science data., Comment: 21 pages, 12 figures, pdflatex, accepted for publication in the Journal of Astronomical Instrumentation
Published: 2016

24. Persistent Asymmetric Structure of Sagittarius A* on Event Horizon Scales

Author: Fish, Vincent L., Johnson, Michael D., Doeleman, Sheperd S., Broderick, Avery E., Psaltis, Dimitrios, Lu, Ru-Sen, Akiyama, Kazunori, Alef, Walter, Algaba, Juan Carlos, Asada, Keiichi, Beaudoin, Christopher, Bertarini, Alessandra, Blackburn, Lindy, Blundell, Ray, Bower, Geoffrey C., Brinkerink, Christiaan, Cappallo, Roger, Chael, Andrew A., Chamberlin, Richard, Chan, Chi-Kwan, Crew, Geoffrey B., Dexter, Jason, Dexter, Matt, Dzib, Sergio A., Falcke, Heino, Freund, Robert, Friberg, Per, Greer, Christopher H., Gurwell, Mark A., Ho, Paul T. P., Honma, Mareki, Inoue, Makoto, Johannsen, Tim, Kim, Junhan, Krichbaum, Thomas P., Lamb, James, León-Tavares, Jonathan, Loeb, Abraham, Loinard, Laurent, MacMahon, David, Marrone, Daniel P., Moran, James M., Mościbrodzka, Monika, Ortiz-León, Gisela N., Oyama, Tomoaki, Özel, Feryal, Plambeck, Richard L., Pradel, Nicolas, Primiani, Rurik A., Rogers, Alan E. E., Rosenfeld, Katherine, Rottmann, Helge, Roy, Alan L., Ruszczyk, Chester, Smythe, Daniel L., SooHoo, Jason, Spilker, Justin, Stone, Jordan, Strittmatter, Peter, Tilanus, Remo P. J., Titus, Michael, Vertatschitsch, Laura, Wagner, Jan, Wardle, John F. C., Weintroub, Jonathan, Woody, David, Wright, Melvyn, Yamaguchi, Paul, Young, André, Young, Ken H., Zensus, J. Anton, and Ziurys, Lucy M.
Subjects: Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Galactic Center black hole Sagittarius A* (Sgr A*) is a prime observing target for the Event Horizon Telescope (EHT), which can resolve the 1.3 mm emission from this source on angular scales comparable to that of the general relativistic shadow. Previous EHT observations have used visibility amplitudes to infer the morphology of the millimeter-wavelength emission. Potentially much richer source information is contained in the phases. We report on 1.3 mm phase information on Sgr A* obtained with the EHT on a total of 13 observing nights over 4 years. Closure phases, the sum of visibility phases along a closed triangle of interferometer baselines, are used because they are robust against phase corruptions introduced by instrumentation and the rapidly variable atmosphere. The median closure phase on a triangle including telescopes in California, Hawaii, and Arizona is nonzero. This result conclusively demonstrates that the millimeter emission is asymmetric on scales of a few Schwarzschild radii and can be used to break 180-degree rotational ambiguities inherent from amplitude data alone. The stability of the sign of the closure phase over most observing nights indicates persistent asymmetry in the image of Sgr A* that is not obscured by refraction due to interstellar electrons along the line of sight., Comment: 11 pages, accepted to ApJ
Published: 2016
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25. New volume translation functions for biodiesel density prediction with the Peng-Robinson Equation of state in terms of its raw materials

Author: Salgueiro, Gutierri, de Moraes, Marcellus, Pessoa, Fernando, Cavalcante, Raquel, and Young, André
Published: 2021
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26. Impact of biodiesel production on a soybean biorefinery

Author: Barreiros, Thaís, Young, André, Cavalcante, Raquel, and Queiroz, Eduardo
Published: 2020
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27. Propylene glycol from glycerol: Process evaluation and break-even price determination

Author: Jiménez, Roberto X., Young, André F., and Fernandes, Heloisa L.S.
Published: 2020
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28. Vapor-liquid equilibrium of binary systems with EoS/GE models at low pressure: Revisiting the Heidemann-Kokal Mixing Rule

Author: Young, André F., Magalhães, Gabriela D.B., Pessoa, Fernando L.P., and Ahón, Víctor R.R.
Published: 2018
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29. Life cycle assessment of biodiesel produced by the methylic-alkaline and ethylic-enzymatic routes

Author: Cristina Santos de Mello, Marcia, Gomes D'Amato Villardi, Hugo, Ferreira Young, André, Luiz Pellegrini Pessoa, Fernando, and Medeiros Salgado, Andrea
Published: 2017
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30. Comparison of volume translation and co-volume functions applied in the Peng-Robinson EoS for volumetric corrections

Author: Young, André F., Pessoa, Fernando L.P., and Ahón, Victor R.R.
Published: 2017
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31. Biodiesel production by the methylic-alkaline and ethylic-enzymatic routes: Discussion of some environmental aspects

Author: de Mello, Marcia, Young, André, Villardi, Hugo, Pessoa, Fernando, and Salgado, Andrea
Published: 2017
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32. R2DBE: A Wideband Digital Backend for the Event Horizon Telescope

Author: Vertatschitsch, Laura, Primiani, Rurik, Young, André, Weintroub, Jonathan, Crew, Geoffrey B., McWhirter, Stephen R., Beaudoin, Christopher, Doeleman, Sheperd, and Blackburn, Lindy
Published: 2015
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33. Prediction of Nutritional Requirements for Children’s Growth and Adolescents using Machine Learning

Author: Hermanto, Agus, primary, Gumelar, Agustinus Bimo, additional, Ongkodjojo, Evelyn, additional, Khudrati, Wilson Christianto, additional, Young, Andre, additional, Ano Djoka, Maria Magdalena, additional, Julian, Alvin, additional, Liona Dewi, Dewa Ayu, additional, and Tahalele, Paul L, additional
Published: 2022
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34. 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, 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, and Zhao, Shan-Shan
Abstract: 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.
Published: 2022

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

Author: 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, 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, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bauböck, Michi, 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, 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, Mariafelcia, 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, Garcia, Roberto, Fentaz, Olivier, Goddi, Ciriaco, Gómez-Ruiz, Arturo L, Gómez, José L, Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Haworth, Kari, Hecht, Michael H, Hesper, Ronald, Herumann, Dirk, Ho, Luis C, Ho, Paul, Honman, 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, Hunhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofugi, 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, Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D, Menten, Karl M, Michalik, Daniel, Mizuno, Izumi, Moran, James M, Moriyama, Kotaro, Muller, Cornelia, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, 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, Oh, Junghwan, Okino, Hiroki, Ortiz-Leon, Gisela N, Oyama, Tomoaki, Palumbo, Daniel C M, Paraschos, Georgios, Park, Jongho, Parsons, Harriet, 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, Romero-Cañizales, Cristina, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L, Ruiz, Ignacio, Ruszczyk, Chet, Rygl, Kazi L J, Sanchez, Salvador, Sánchez-Argüelles, David, Sánchez-Porta, Miguel, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfel, 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, 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, Witzel, Gunther, Wondrak, Michael F, Wu, Qingwen, Yamaguchi, Paul, Young, Andre, Young, Ken, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, Zhao, Shan-Shan, 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, 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, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bauböck, Michi, 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, 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, Mariafelcia, 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, Garcia, Roberto, Fentaz, Olivier, Goddi, Ciriaco, Gómez-Ruiz, Arturo L, Gómez, José L, Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Haworth, Kari, Hecht, Michael H, Hesper, Ronald, Herumann, Dirk, Ho, Luis C, Ho, Paul, Honman, 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, Hunhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofugi, 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, Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D, Menten, Karl M, Michalik, Daniel, Mizuno, Izumi, Moran, James M, Moriyama, Kotaro, Muller, Cornelia, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, 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, Oh, Junghwan, Okino, Hiroki, Ortiz-Leon, Gisela N, Oyama, Tomoaki, Palumbo, Daniel C M, Paraschos, Georgios, Park, Jongho, Parsons, Harriet, 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, Romero-Cañizales, Cristina, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L, Ruiz, Ignacio, Ruszczyk, Chet, Rygl, Kazi L J, Sanchez, Salvador, Sánchez-Argüelles, David, Sánchez-Porta, Miguel, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfel, 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, 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, Witzel, Gunther, Wondrak, Michael F, Wu, Qingwen, Yamaguchi, Paul, Young, Andre, Young, Ken, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan
Abstract: 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.
Published: 2022

36. Millimeter Light Curves of Sagittarius A* Observed during the 2017 Event Horizon Telescope Campaign

Author: 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, 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, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bauböck, Michi, 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, 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, Mariafelcia, 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, Garcia, Roberto, Gentaz, Olivier, Goddi, Ciriaco, Gómez-Ruiz, Arturo L, Gómez, José L, Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Haworth, Kari, Hecht, Michael H, Hesper, Ronald, Herumann, Dirk, Ho, Luis C, Ho, Paul, Honman, 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, Hunhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofugi, 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, Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D, Menten, Karl M, Michalik, Daniel, Mizuno, Izumi, Moran, James M, Moriyama, Kotaro, Muller, Cornelia, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, 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, Oh, Junghwan, Okino, Hiroki, Ortiz-Leon, Gisela N, Oyama, Tomoaki, Palumbo, Daniel C M, Paraschos, Georgios, Park, Jongho, Parsons, Harriet, 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, Romero-Cañizales, Cristina, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L, Ruiz, Ignacio, Ruszczyk, Chet, Rygl, Kazi L J, Sanchez, Salvador, Sánchez-Argüelles, David, Sánchez-Porta, Miguel, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfel, 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, 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, Witzel, Gunther, Wondrak, Michael F, Wu, Qingwen, Yamaguchi, Paul, Young, Andre, Young, Ken, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, Zhao, Shan-Shan, Boland, Wilfred, Özel, Feryal, Porth, Oliver, 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, 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, Bach, Uwe, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bauböck, Michi, 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, 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, Mariafelcia, 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, Garcia, Roberto, Gentaz, Olivier, Goddi, Ciriaco, Gómez-Ruiz, Arturo L, Gómez, José L, Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, Haworth, Kari, Hecht, Michael H, Hesper, Ronald, Herumann, Dirk, Ho, Luis C, Ho, Paul, Honman, 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, Hunhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofugi, 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, Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D, Menten, Karl M, Michalik, Daniel, Mizuno, Izumi, Moran, James M, Moriyama, Kotaro, Muller, Cornelia, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, 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, Oh, Junghwan, Okino, Hiroki, Ortiz-Leon, Gisela N, Oyama, Tomoaki, Palumbo, Daniel C M, Paraschos, Georgios, Park, Jongho, Parsons, Harriet, 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, Romero-Cañizales, Cristina, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L, Ruiz, Ignacio, Ruszczyk, Chet, Rygl, Kazi L J, Sanchez, Salvador, Sánchez-Argüelles, David, Sánchez-Porta, Miguel, Sasada, Mahito, Satapathy, Kaushik, Savolainen, Tuomas, Schloerb, F. Peter, Schonfel, 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, 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, Witzel, Gunther, Wondrak, Michael F, Wu, Qingwen, Yamaguchi, Paul, Young, Andre, Young, Ken, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, Zhao, Shan-Shan, Boland, Wilfred, Özel, Feryal, and Porth, Oliver
Abstract: The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A* (Sgr A*), in the Galactic Center on 2017 April 5–11 in the 1.3 mm wavelength band. At the same time, interferometric array data from the Atacama Large Millimeter/submillimeter Array and the Submillimeter Array were collected, providing Sgr A* light curves simultaneous with the EHT observations. These data sets, complementing the EHT very long baseline interferometry, are characterized by a cadence and signal-to-noise ratio previously unattainable for Sgr A* at millimeter wavelengths, and they allow for the investigation of source variability on timescales as short as a minute. While most of the light curves correspond to a low variability state of Sgr A*, the April 11 observations follow an X-ray flare and exhibit strongly enhanced variability. All of the light curves are consistent with a red-noise process, with a power spectral density (PSD) slope measured to be between −2 and −3 on timescales between 1 minute and several hours. Our results indicate a steepening of the PSD slope for timescales shorter than 0.3 hr. The spectral energy distribution is flat at 220 GHz, and there are no time lags between the 213 and 229 GHz frequency bands, suggesting low optical depth for the event horizon scale source. We characterize Sgr A*'s variability, highlighting the different behavior observed just after the X-ray flare, and use Gaussian process modeling to extract a decorrelation timescale and a PSD slope. We also investigate the systematic calibration uncertainties by analyzing data from independent data reduction pipelines.
Published: 2022

37. Experimental methodology for CO2 capture and sodium bicarbonate synthesis with producedwater from oil industry.

Author: Villardi, Hugo Gomes D'Amato, Yokoyama, Lidia, Young, Andre, Veiga, Andrea Azevedo, and Pagnin, Sergio
Subjects: SODIUM bicarbonate, PETROLEUM industry, OIL field brines, CARBON dioxide in water, PETROLEUM production, PETROLEUM
Abstract: Produced water is the main residue from the petroleum extraction industry. Other critical factor in this sector is carbon dioxide emissions. This work presents a solution proposal for both problems throughout the development of an apparatus which allows the synthesis of salts dissolved in produced water with CO2 capture. The experimental unit developed in this work was based on the Solvay process, to convert sodium chloride (NaCl) into sodium bicarbonate (NaHCO3) from synthetic produced water and carbon dioxide (CO2). No previous work used the combination of produced water and CO2 aiming at the synthesis of new products. Four steps were made with different experimental setups. The best outcome for the reaction of bicarbonate attained a conversion of 44.5% of sodium chloride into sodium bicarbonate and capture of 250,000 tons of carbon dioxide per year. A preliminary financial analysis indicates an annual revenue of US$ 126,607,292.31 in sodium bicarbonate and ammonium chloride and US$ 2,862,897.23 in carbon credits per year. The studied methodology can be used as a starting point for new experimental works that have the purpose to obtain salts from produced water and can help for better understanding its potential as carbon capture agent and a source of valuable products, contributing to the reduction of the environmental impact and adding value to the production chain. [ABSTRACT FROM AUTHOR]
Published: 2022
Full Text: View/download PDF

38. Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution

Author: Kim, Jae-Young, Krichbaum, Thomas P., Broderick, Avery E., Wielgus, Maciek, Blackburn, Lindy, Gomez, Jose L., Johnson, Michael D., Bouman, Katherine L., Chael, Andrew, Akiyama, Kazunori, Jorstad, Svetlana, Marscher, Alan P., Issaoun, Sara, Janssen, Michael, Chan, Chi-kwan, Savolainen, Tuomas, Pesce, Dominic W., Ozel, Feryal, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Boland, Wilfred, Bower, Geoffrey C., Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broguiere, Dominique, Bronzwaer, Thomas, Byun, Do-Young, Carlstrom, John E., Chatterjee, Shami, Chatterjee, Koushik, Chen, Ming-Tang, Chen, Yongjun, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crew, Geoffrey B., Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, 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., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Ikeda, Shiro, Inoue, Makoto, James, David J., Jannuzi, Buell T., Jeter, Britton, Jiang, Wu, Jimenez-Rosales, Alejandra, Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Junhan, Kim, Jongsoo, Kino, Motoki, Koay, Jun Yi, Koch, Patrick M., Koyama, Shoko, Kramer, Michael, Kramer, Carsten, Kuo, Cheng-Yu, Lauer, Tod R., 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, Markoff, Sera, Marrone, Daniel P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Palumbo, Daniel C. M., Park, Jongho, Patel, Nimesh, Pen, Ue-Li, Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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, Ryan, Benjamin R., Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-Arguelles, David, Sasada, Mahito, Schloerb, F. Peter, Schuster, Karl-Friedrich, Shao, Lijing, Shen, Zhiqiang, Small, Des, Sohn, Bong Won, SooHoo, Jason, Tazaki, Fumie, Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toma, Kenji, Torne, Pablo, Trent, Tyler, Traianou, Efthalia, Trippe, Sascha, Tsuda, Shuichiro, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Wardle, John, Ward-Thompson, Derek, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wong, George N., Wu, Qingwen, Yoon, Doosoo, Young, Andre, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guangyao, Zhao, Shan-Shan, Zhu, Ziyan, Algaba, Juan-Carlos, Allardi, Alexander, Amestica, Rodrigo, Anczarski, Jadyn, Bach, Uwe, Baganoff, Frederick K., Beaudoin, Christopher, Benson, Bradford A., Berthold, Ryan, Blanchard, Jay M., Blundell, Ray, Bustamente, Sandra, Cappallo, Roger, Castillo-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, Coulson, Iain M., Crowley, Joseph, Derome, Mark, Dexter, Matthew, Dornbusch, Sven, Dudevoir, Kevin A., Dzib, Sergio A., Eckart, Andreas, Eckert, Chris, Erickson, Neal R., Everett, Wendeline B., Faber, Aaron, Farah, Joseph R., Fath, Vernon, Folkers, Thomas W., Forbes, David C., Freund, Robert, Gomez-Ruiz, Arturo, I, Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, Jiang, Homin, John, David, Kamble, Atish, Keisler, Ryan, Kimura, Kimihiro, Kono, Yusuke, Kubo, Derek, Kuroda, John, Lacasse, Richard, Laing, Robert A., Leitch, Erik M., Li, Chao-Te, Lin, Lupin C-C, Liu, Ching-Tang, Liu, Kuan-Yu, Lu, Li-Ming, Marson, Ralph G., Martin-Cocher, Pierre L., Massingill, Kyle D., Matulonis, Callie, McColl, Martin P., McWhirter, Stephen R., Messias, Hugo, Meyer-Zhao, Zheng, Michalik, Daniel, Montana, Alfredo, Montgomerie, William, Mora-Klein, Matias, Muders, Dirk, Nadolski, Andrew, Navarro, Santiago, Neilsen, Joseph, Nguyen, Chi H., Nishioka, Hiroaki, Norton, Timothy, Nowak, Michael A., Nystrom, George, Ogawa, Hideo, Oshiro, Peter, Parsons, Harriet, Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. K., Srinivasan, Ranjani, Stahm, William, Stark, Antony A., Story, Kyle, Timmer, Sjoerd T., Vertatschitsch, Laura, Walther, Craig, Wei, Ta-Shun, Whitehorn, Nathan, Whitney, Alan R., Woody, David P., Wouterloot, Jan G. A., Wright, Melvin, Yamaguchi, Paul, Yu, Chen-Yu, Zeballos, Milagros, Zhang, Shuo, Ziurys, Lucy, Kim, Jae-Young, Krichbaum, Thomas P., Broderick, Avery E., Wielgus, Maciek, Blackburn, Lindy, Gomez, Jose L., Johnson, Michael D., Bouman, Katherine L., Chael, Andrew, Akiyama, Kazunori, Jorstad, Svetlana, Marscher, Alan P., Issaoun, Sara, Janssen, Michael, Chan, Chi-kwan, Savolainen, Tuomas, Pesce, Dominic W., Ozel, Feryal, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Boland, Wilfred, Bower, Geoffrey C., Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broguiere, Dominique, Bronzwaer, Thomas, Byun, Do-Young, Carlstrom, John E., Chatterjee, Shami, Chatterjee, Koushik, Chen, Ming-Tang, Chen, Yongjun, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crew, Geoffrey B., Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, 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., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Ikeda, Shiro, Inoue, Makoto, James, David J., Jannuzi, Buell T., Jeter, Britton, Jiang, Wu, Jimenez-Rosales, Alejandra, Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Junhan, Kim, Jongsoo, Kino, Motoki, Koay, Jun Yi, Koch, Patrick M., Koyama, Shoko, Kramer, Michael, Kramer, Carsten, Kuo, Cheng-Yu, Lauer, Tod R., 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, Markoff, Sera, Marrone, Daniel P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Palumbo, Daniel C. M., Park, Jongho, Patel, Nimesh, Pen, Ue-Li, Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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, Ryan, Benjamin R., Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-Arguelles, David, Sasada, Mahito, Schloerb, F. Peter, Schuster, Karl-Friedrich, Shao, Lijing, Shen, Zhiqiang, Small, Des, Sohn, Bong Won, SooHoo, Jason, Tazaki, Fumie, Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toma, Kenji, Torne, Pablo, Trent, Tyler, Traianou, Efthalia, Trippe, Sascha, Tsuda, Shuichiro, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Wardle, John, Ward-Thompson, Derek, Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wong, George N., Wu, Qingwen, Yoon, Doosoo, Young, Andre, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guangyao, Zhao, Shan-Shan, Zhu, Ziyan, Algaba, Juan-Carlos, Allardi, Alexander, Amestica, Rodrigo, Anczarski, Jadyn, Bach, Uwe, Baganoff, Frederick K., Beaudoin, Christopher, Benson, Bradford A., Berthold, Ryan, Blanchard, Jay M., Blundell, Ray, Bustamente, Sandra, Cappallo, Roger, Castillo-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, Coulson, Iain M., Crowley, Joseph, Derome, Mark, Dexter, Matthew, Dornbusch, Sven, Dudevoir, Kevin A., Dzib, Sergio A., Eckart, Andreas, Eckert, Chris, Erickson, Neal R., Everett, Wendeline B., Faber, Aaron, Farah, Joseph R., Fath, Vernon, Folkers, Thomas W., Forbes, David C., Freund, Robert, Gomez-Ruiz, Arturo, I, Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, Jiang, Homin, John, David, Kamble, Atish, Keisler, Ryan, Kimura, Kimihiro, Kono, Yusuke, Kubo, Derek, Kuroda, John, Lacasse, Richard, Laing, Robert A., Leitch, Erik M., Li, Chao-Te, Lin, Lupin C-C, Liu, Ching-Tang, Liu, Kuan-Yu, Lu, Li-Ming, Marson, Ralph G., Martin-Cocher, Pierre L., Massingill, Kyle D., Matulonis, Callie, McColl, Martin P., McWhirter, Stephen R., Messias, Hugo, Meyer-Zhao, Zheng, Michalik, Daniel, Montana, Alfredo, Montgomerie, William, Mora-Klein, Matias, Muders, Dirk, Nadolski, Andrew, Navarro, Santiago, Neilsen, Joseph, Nguyen, Chi H., Nishioka, Hiroaki, Norton, Timothy, Nowak, Michael A., Nystrom, George, Ogawa, Hideo, Oshiro, Peter, Parsons, Harriet, Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. K., Srinivasan, Ranjani, Stahm, William, Stark, Antony A., Story, Kyle, Timmer, Sjoerd T., Vertatschitsch, Laura, Walther, Craig, Wei, Ta-Shun, Whitehorn, Nathan, Whitney, Alan R., Woody, David P., Wouterloot, Jan G. A., Wright, Melvin, Yamaguchi, Paul, Yu, Chen-Yu, Zeballos, Milagros, Zhang, Shuo, and Ziurys, Lucy
Abstract: 3C 279 is an archetypal blazar with a prominent radio jet that show broadband flux density variability across the entire electromagnetic spectrum. We use an ultra-high angular resolution technique - global Very Long Baseline Interferometry (VLBI) at 1.3 mm (230 GHz) - to resolve the innermost jet of 3C 279 in order to study its fine-scale morphology close to the jet base where highly variable gamma -ray emission is thought to originate, according to various models. The source was observed during four days in April 2017 with the Event Horizon Telescope at 230 GHz, including the phased Atacama Large Millimeter/submillimeter Array (ALMA), at an angular resolution of similar to 20 mu as (at a redshift of z=0.536 this corresponds to similar to 0.13 pc similar to 1700 Schwarzschild radii with a black hole mass M-BH=8x10(8) M-circle dot). Imaging and model-fitting techniques were applied to the data to parameterize the fine-scale source structure and its variation. We find a multicomponent inner jet morphology with the northernmost component elongated perpendicular to the direction of the jet, as imaged at longer wavelengths. The elongated nuclear structure is consistent on all four observing days and across different imaging methods and model-fitting techniques, and therefore appears robust. Owing to its compactness and brightness, we associate the northern nuclear structure as the VLBI core. This morphology can be interpreted as either a broad resolved jet base or a spatially bent jet. We also find significant day-to-day variations in the closure phases, which appear most pronounced on the triangles with the longest baselines. Our analysis shows that this variation is related to a systematic change of the source structure. Two inner jet components move non-radially at apparent speeds of similar to 15 c and similar to 20 c (similar to 1.3 and similar to 1.7 mu as day(-1), respectively), which more strongly supports the scenario of traveling shocks or instabilities in a be
Published: 2020

39. Psychiatric Admissions Among Undocumented Immigrants at an Urban County Hospital

Author: Du, Senxi, Yang, Helen, Ro, Annie, Huynh, Michael P, Hanlon, Courtney, and Young, Andrew
Published: 2023
Full Text: View/download PDF

40. The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project

Author: Porth, O., Chatterjee, Koushik, Narayan, Ramesh, Gammie, C.F., Mizuno, Y., Anninos, Peter, Davelaar, Jordy, Brinkerink, C.D., Bronzwaer, T.J.W., Falcke, H.D.E., Fraga Encinas, R., Goddi, C., Issaoun, Sara, Janssen, Michael, Mościbrodzka, M.A., Müller, C., Natarajan, Iniyan, Roelofs, Freek, Rossum, D.R. van, Tilanus, R.P.J., Young, Andre, Zhao, S., Zhu, Ziyan, Porth, O., Chatterjee, Koushik, Narayan, Ramesh, Gammie, C.F., Mizuno, Y., Anninos, Peter, Davelaar, Jordy, Brinkerink, C.D., Bronzwaer, T.J.W., Falcke, H.D.E., Fraga Encinas, R., Goddi, C., Issaoun, Sara, Janssen, Michael, Mościbrodzka, M.A., Müller, C., Natarajan, Iniyan, Roelofs, Freek, Rossum, D.R. van, Tilanus, R.P.J., Young, Andre, Zhao, S., and Zhu, Ziyan
Abstract: Contains fulltext : 205960.pdf (preprint version ) (Open Access)
Published: 2019

41. First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring

Author: Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Blackburn, Lindy, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., 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, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crew, Geoffrey B., Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph P., Falcke, Heino, Fish, Vincent L., Fomalont, Ed, Fraga-Encinas, Raquel, Friberg, Per, Fromm, Christian M., Gomez, Jose L., Galisonl, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Ikeda, Shiro, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, 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, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin, Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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, Ryan, Benjamin R., Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-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, Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toma, Kenji, Torne, Pablo, Trent, Tyler, 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, Young, Andre, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guangyao, Zhao, Shan-Shan, Zhu, Ziyan, Anczarski, Jadyn, Baganoff, Frederick K., Eckart, Andreas, Farah, Joseph R., Haggard, Daryl, Meyer-Zhao, Zheng, Michalik, Daniel, Nadolski, Andrew, Neilsen, Joseph, Nishioka, Hiroaki, Nowak, Michael A., Pradel, Nicolas, Primiani, Rurik A., Souccar, Kamal, Vertatschitsch, Laura, Yamaguchi, Paul, Zhang, Shuo, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Blackburn, Lindy, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., 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, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crew, Geoffrey B., Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph P., Falcke, Heino, Fish, Vincent L., Fomalont, Ed, Fraga-Encinas, Raquel, Friberg, Per, Fromm, Christian M., Gomez, Jose L., Galisonl, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Ikeda, Shiro, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, 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, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin, Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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, Ryan, Benjamin R., Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-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, Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toma, Kenji, Torne, Pablo, Trent, Tyler, 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, Young, Andre, Young, Ken, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guangyao, Zhao, Shan-Shan, Zhu, Ziyan, Anczarski, Jadyn, Baganoff, Frederick K., Eckart, Andreas, Farah, Joseph R., Haggard, Daryl, Meyer-Zhao, Zheng, Michalik, Daniel, Nadolski, Andrew, Neilsen, Joseph, Nishioka, Hiroaki, Nowak, Michael A., Pradel, Nicolas, Primiani, Rurik A., Souccar, Kamal, Vertatschitsch, Laura, Yamaguchi, Paul, and Zhang, Shuo
Abstract: The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data. To this end, we construct a large library of models based on general relativistic magnetohydrodynamic (GRMHD) simulations and synthetic images produced by general relativistic ray tracing. We compare the observed visibilities with this library and confirm that the asymmetric ring is consistent with earlier predictions of strong gravitational lensing of synchrotron emission from a hot plasma orbiting near the black hole event horizon. The ring radius and ring asymmetry depend on black hole mass and spin, respectively, and both are therefore expected to be stable when observed in future EHT campaigns. Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity. If the black hole spin and M87's large scale jet are aligned, then the black hole spin vector is pointed away from Earth. Models in our library of non-spinning black holes are inconsistent with the observations as they do not produce sufficiently powerful jets. At the same time, in those models that produce a sufficiently powerful jet, the latter is powered by extraction of black hole spin energy through mechanisms akin to the Blandford-Znajek process. We briefly consider alternatives to a black hole for the central compact object. Analysis of existing EHT polarization data and data taken simultaneously at other wavelengths will soon enable new tests of the GRMHD models, as will future EHT campaigns at 230 and 345 GHz.
Published: 2019

42. First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole

Author: Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Blackburn, Lindy, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., 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, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crew, Geoffrey B., Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph P., Falcke, Heino, Fish, Vincent L., Fomalont, Ed, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Gomez, Jose L., Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Ikeda, Shiro, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, 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, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin, Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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, Ryan, Benjamin R., Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-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, Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toma, Kenji, Torne, Pablo, Trent, Tyler, 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, Young, Ken, Young, Andre, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guangyao, Zhao, Shan-Shan, Zhu, Ziyan, Algaba, Juan-Carlos, Allardi, Alexander, Amestica, Rodrigo, Anczarski, Jadyn, Bach, Uwe, Baganoff, Frederick K., Beaudoin, Christopher, Benson, Bradford A., Berthold, Ryan, Blanchard, Jay M., Blundell, Ray, Bustamente, Sandra, Cappallo, Roger, Castillo-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, Coulson, Iain M., Crawford, Thomas M., Crowley, Joseph, David, John, Derome, Mark, Dexter, Matthew, Dornbusch, Sven, Dudevoir, Kevin A., Dzib, Sergio A., Eckart, Andreas, Eckert, Chris, Erickson, Neal R., Everett, Wendeline B., Faber, Aaron, Farah, Joseph R., Fath, Vernon, Folkers, Thomas W., Forbes, David C., Freund, Robert, Gomez-Ruiz, Arturo I., Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, Jiang, Homin, Kamble, Atish, Keisler, Ryan, Kimura, Kimihiro, Kono, Yusuke, Kubo, Derek, Kuroda, John, Lacasse, Richard, Laing, Robert A., Leitch, Erik M., Li, Chao-Te, Lin, Lupin C. -C., Liu, Ching-Tang, Liu, Kuan-Yu, Lu, Li-Ming, Marson, Ralph G., Martin-Cocher, Pierre L., Massingill, Kyle D., Matulonis, Callie, McColl, Martin P., McWhirter, Stephen R., Messias, Hugo, Meyer-Zhao, Zheng, Michalik, Daniel, Montana, Alfredo, Montgomerie, William, Mora-Klein, Matias, Muders, Dirk, Nadolski, Andrew, Navarro, Santiago, Neilsen, Joseph, Nguyen, Chi H., Nishioka, Hiroaki, Norton, Timothy, Nowak, Michael A., Nystrom, George, Ogawa, Hideo, Oshiro, Peter, Parsons, Harriet, Paine, Scott N., Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. K., Srinivasan, Ranjani, Stahm, William, Stark, Anthony A., Story, Kyle, Timmer, Sjoerd T., Vertatschitsch, Laura, Walther, Craig, Wei, Ta-Shun, Whitehorn, Nathan, Whitney, Alan R., Woody, David P., Wouterloot, Jan G. A., Wright, Melvin, Yamaguchi, Paul, Yu, Chen-Yu, Zeballos, Milagros, Zhang, Shuo, Ziurys, Lucy, Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David, Balokovic, Mislav, Barrett, John, Bintley, Dan, Blackburn, Lindy, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., 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, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crew, Geoffrey B., Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph P., Falcke, Heino, Fish, Vincent L., Fomalont, Ed, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Gomez, Jose L., Galison, Peter, Gammie, Charles F., Garcia, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, 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., Ikeda, Shiro, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, 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, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Lobanov, Andrei P., Loinard, Laurent, Lonsdale, Colin, Lu, Ru-Sen, MacDonald, Nicholas R., Mao, Jirong, Markoff, Sera, Marrone, Daniel P., Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn D., Medeiros, Lia, Menten, Karl M., Mizuno, Yosuke, Mizuno, Izumi, Moran, James M., Moriyama, Kotaro, Moscibrodzka, Monika, Mueller, Cornelia, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Ozel, Feryal, Palumbo, Daniel C. M., Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Prather, Ben, Preciado-Lopez, 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, Ryan, Benjamin R., Rygl, Kazi L. J., Sanchez, Salvador, Sanchez-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, Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Toma, Kenji, Torne, Pablo, Trent, Tyler, 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, Young, Ken, Young, Andre, Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guangyao, Zhao, Shan-Shan, Zhu, Ziyan, Algaba, Juan-Carlos, Allardi, Alexander, Amestica, Rodrigo, Anczarski, Jadyn, Bach, Uwe, Baganoff, Frederick K., Beaudoin, Christopher, Benson, Bradford A., Berthold, Ryan, Blanchard, Jay M., Blundell, Ray, Bustamente, Sandra, Cappallo, Roger, Castillo-Dominguez, Edgar, Chang, Chih-Cheng, Chang, Shu-Hao, Chang, Song-Chu, Chen, Chung-Chen, Chilson, Ryan, Chuter, Tim C., Rosado, Rodrigo Cordova, Coulson, Iain M., Crawford, Thomas M., Crowley, Joseph, David, John, Derome, Mark, Dexter, Matthew, Dornbusch, Sven, Dudevoir, Kevin A., Dzib, Sergio A., Eckart, Andreas, Eckert, Chris, Erickson, Neal R., Everett, Wendeline B., Faber, Aaron, Farah, Joseph R., Fath, Vernon, Folkers, Thomas W., Forbes, David C., Freund, Robert, Gomez-Ruiz, Arturo I., Gale, David M., Gao, Feng, Geertsema, Gertie, Graham, David A., Greer, Christopher H., Grosslein, Ronald, Gueth, Frederic, Haggard, Daryl, Halverson, Nils W., Han, Chih-Chiang, Han, Kuo-Chang, Hao, Jinchi, Hasegawa, Yutaka, Henning, Jason W., Hernandez-Gomez, Antonio, Herrero-Illana, Ruben, Heyminck, Stefan, Hirota, Akihiko, Hoge, James, Huang, Yau-De, Impellizzeri, C. M. Violette, Jiang, Homin, Kamble, Atish, Keisler, Ryan, Kimura, Kimihiro, Kono, Yusuke, Kubo, Derek, Kuroda, John, Lacasse, Richard, Laing, Robert A., Leitch, Erik M., Li, Chao-Te, Lin, Lupin C. -C., Liu, Ching-Tang, Liu, Kuan-Yu, Lu, Li-Ming, Marson, Ralph G., Martin-Cocher, Pierre L., Massingill, Kyle D., Matulonis, Callie, McColl, Martin P., McWhirter, Stephen R., Messias, Hugo, Meyer-Zhao, Zheng, Michalik, Daniel, Montana, Alfredo, Montgomerie, William, Mora-Klein, Matias, Muders, Dirk, Nadolski, Andrew, Navarro, Santiago, Neilsen, Joseph, Nguyen, Chi H., Nishioka, Hiroaki, Norton, Timothy, Nowak, Michael A., Nystrom, George, Ogawa, Hideo, Oshiro, Peter, Parsons, Harriet, Paine, Scott N., Penalver, Juan, Phillips, Neil M., Poirier, Michael, Pradel, Nicolas, Primiani, Rurik A., Raffin, Philippe A., Rahlin, Alexandra S., Reiland, George, Risacher, Christopher, Ruiz, Ignacio, Saez-Madain, Alejandro F., Sassella, Remi, Schellart, Pim, Shaw, Paul, Silva, Kevin M., Shiokawa, Hotaka, Smith, David R., Snow, William, Souccar, Kamal, Sousa, Don, Sridharan, T. K., Srinivasan, Ranjani, Stahm, William, Stark, Anthony A., Story, Kyle, Timmer, Sjoerd T., Vertatschitsch, Laura, Walther, Craig, Wei, Ta-Shun, Whitehorn, Nathan, Whitney, Alan R., Woody, David P., Wouterloot, Jan G. A., Wright, Melvin, Yamaguchi, Paul, Yu, Chen-Yu, Zeballos, Milagros, Zhang, Shuo, and Ziurys, Lucy
Abstract: When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 +/- 3 mu as, which is circular and encompasses a central depression in brightness with a flux ratio greater than or similar to 10: 1. The emission ring is recovered using different calibration and imaging schemes, with its diameter and width remaining stable over four different observations carried out in different days. Overall, the observed image is consistent with expectations for the shadow of a Kerr black hole as predicted by general relativity. The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole. We compare our images to an extensive library of ray-traced general-relativistic magnetohydrodynamic simulations of black holes and derive a central mass of M = (6.5 +/- 0.7) x 10(9) M-circle dot. Our radio-wave observations thus provide powerful evidence for the presence of supermassive black holes in centers of galaxies and as the central engines of active galactic nuclei. They also present a new tool to explore gravity in its most extreme limit and on a mass scale that was so far not accessible.
Published: 2019

43. COVID-19-Related Emergency Department Visits Among Undocumented Patients in Los Angeles County

Author: Huynh, Michael P., Du, Senxi, Hanlon, Courtney, Yang, Helen, Young, Andrew, and Ro, Annie
Published: 2023
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44. Experimental methodology for CO2capture and sodium bicarbonate synthesis with producedwater from oil industry

Author: Villardi, Hugo Gomes D’Amato, Yokoyama, Lidia, Young, Andre, Veiga, Andrea Azevedo, and Pagnin, Sergio
Abstract: Produced water is the main residue from the petroleum extraction industry. Other critical factor in this sector is carbon dioxide emissions. This work presents a solution proposal for both problems throughout the development of an apparatus which allows the synthesis of salts dissolved in produced water with CO2capture. The experimental unit developed in this work was based on the Solvay process, to convert sodium chloride (NaCl) into sodium bicarbonate (NaHCO3) from synthetic produced water and carbon dioxide (CO2). No previous work used the combination of produced water and CO2aiming at the synthesis of new products. Four steps were made with different experimental setups. The best outcome for the reaction of bicarbonate attained a conversion of 44.5% of sodium chloride into sodium bicarbonate and capture of 250,000 tons of carbon dioxide per year. A preliminary financial analysis indicates an annual revenue of US$ 126,607,292.31 in sodium bicarbonate and ammonium chloride and US$ 2,862,897.23 in carbon credits per year. The studied methodology can be used as a starting point for new experimental works that have the purpose to obtain salts from produced water and can help for better understanding its potential as carbon capture agent and a source of valuable products, contributing to the reduction of the environmental impact and adding value to the production chain.
Published: 2022
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45. Relations among atmospheric structure, refraction, and extinction

Author: Young, Andrew T.
Subjects: Refraction, Extinction, Atmospheric Structure, Polytropes, Lapse Rate, Inverse Problems, Standard Atmosphere, Physics, QC1-999
Abstract: The refraction and extinction in the Earth’s atmosphere depend on the atmosphere’s structure, so it was natural to try to infer that structure from optical observations. Efforts to extract structure from observed refractions led to proof that this is possible only below the astronomical horizon. Direct studies of the real atmosphere show complicated, variable structure. The complex history of relations between structure and refraction is outlined by citing some important works.
Published: 2023
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46. Did Monge really explain inferior mirages?

Author: Young, Andrew T.
Subjects: Monge, mirages, refraction, meteorological optics, apparent horizon, horizon dip, history of optics, Physics, QC1-999
Abstract: Gaspard Monge has received undue credit for his observations of mirages in 1798 in Egypt. He did not discover inferior mirages; they were known to sailors before 1687, and the term mirage had entered the French literature in 1753. Monge’s “total reflection” explanation for them was seriously flawed; it had already been considered and rejected by Gruber and by Büsch, and was promptly criticized by others. Yet he continues to be given credit for the first scientific explanation of mirages; and his false total-reflection mechanism survives today in some textbooks. Apparently this is due to its superficial simplicity, which appeals to novices.
Published: 2022
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47. Hydrogen Sulphide Scavenging Simulation in HYSYS

Author: Young, André, Pessoa, Fernando, and Queiroz, Eduardo
Published: 2016
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48. A VLBI receiving system for the South Pole Telescope

Author: Kim, Junhan, primary, Marrone, Daniel P., primary, Beaudoin, Christopher, primary, Carlstrom, John E., primary, Doeleman, Sheperd S., primary, Folkers, Thomas W., primary, Forbes, David, primary, Greer, Christopher H., primary, Lauria, Eugene F., primary, Massingill, Kyle D., primary, Mayer, Evan, primary, Nguyen, Chi H., primary, Reiland, George, primary, SooHoo, Jason, primary, Vertatschitsch, Laura, primary, Weintroub, Jonathan, primary, Young, Andre, primary, and Stark, Antony A., primary
Published: 2018
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49. Design and Economic Evaluation of Alternatives to Effluents Treatment on Biodiesel Production from Soybean Oil and Palm Oil

Author: Young, André F., Pessoa, Fernando L.P., and Queiroz, Eduardo M.
Published: 2015
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50. Fast and Accurate Analysis of Reflector Antennas With Phased Array Feeds Including Multiple Reflections Between Feed and Reflector

Author: Iupikov, Oleg A., primary, Maaskant, Rob, additional, Ivashina, Marianna V., additional, Young, Andre, additional, and Kildal, Per-Simon, additional
Published: 2014
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