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Your search keyword '"Mulaudzi, Wanga"' showing total 9 results
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9 results on '"Mulaudzi, Wanga"'

1. The putative center in NGC 1052

Author

Baczko, Anne-Kathrin, Kadler, Matthias, Ros, Eduardo, Fromm, Christian M., Wielgus, Maciek, Perucho, Manel, Krichbaum, Thomas P., Baloković, Mislav, Blackburn, Lindy, Chan, Chi-kwan, Issaoun, Sara, Janssen, Michael, Ricci, Luca, Akiyama, Kazunori, Albentosa-Ruíz, Ezequiel, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Bach, Uwe, Ball, David, Bandyopadhyay, Bidisha, Barrett, John, Bauböck, Michi, Benson, Bradford A., Bintley, Dan, Blundell, Raymond, Bouman, Katherine L., Bower, Geoffrey C., Boyce, Hope, Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Broguiere, Dominique, Bronzwaer, Thomas, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E., Ceccobello, Chiara, Chael, Andrew, 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, Dahale, Rohan, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Dhruv, Vedant, Dihingia, Indu K., Doeleman, Sheperd S., Dougall, Sean Taylor, Dzib, Sergio A., Eatough, Ralph P., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fish, Vincent L., Fomalont, Edward, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fuentes, Antonio, Galison, Peter, Gammie, Charles F., García, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, Gómez-Ruiz, Arturo I., Gómez, José L., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, 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., Impellizzeri, C. M. Violette, Inoue, Makoto, James, David J., Jannuzi, Buell T., 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, Joana A., Kramer, Michael, 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., Lowitz, Amy E., 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, Moscibrodzka, Monika, Mulaudzi, Wanga, Müller, Cornelia, Müller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, Nagai, Hiroshi, Nagar, Neil M., Nair, Dhanya G., Nakamura, Masanori, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Fuentes, Santiago Navarro, Neilsen, Joey, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A., Oh, Junghwan, Okino, Hiroki, Sánchez, Héctor Raúl Olivares, 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., Prather, Ben, Preciado-López, Jorge A., Principe, Giacomo, Psaltis, Dimitrios, Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Raymond, Alexander W., Ricarte, Angelo, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, 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, Salas, León David Sosapanta, Souccar, Kamal, Stanway, Joshua S., Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Torne, Pablo, Toscano, Teresa, 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, Washington, Jasmin E., Weintroub, Jonathan, Wharton, Robert, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, André, Young, Ken, Younsi, Ziri, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, and Zhao, Guang-Yao

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

Many active galaxies harbor powerful relativistic jets, however, the detailed mechanisms of their formation and acceleration remain poorly understood. To investigate the area of jet acceleration and collimation with the highest available angular resolution, we study the innermost region of the bipolar jet in the nearby low-ionization nuclear emission-line region (LINER) galaxy NGC 1052. We combined observations of NGC 1052 taken with VLBA, GMVA, and EHT over one week in the spring of 2017. For the first time, NGC 1052 was detected with the EHT, providing a size of the central region in-between both jet bases of 250 RS (Schwarzschild radii) perpendicular to the jet axes. This size estimate supports previous studies of the jets expansion profile which suggest two breaks of the profile at around 300 RS and 10000 RS distances to the core. Furthermore, we estimated the magnetic field to be 1.25 Gauss at a distance of 22 {\mu}as from the central engine by fitting a synchrotron-self absorption spectrum to the innermost emission feature, which shows a spectral turn-over at about 130 GHz. Assuming a purely poloidal magnetic field, this implies an upper limit on the magnetic field strength at the event horizon of 26000 Gauss, which is consistent with previous measurements. The complex, low-brightness, double-sided jet structure in NGC 1052 makes it a challenge to detect the source at millimeter (mm) wavelengths. However, our first EHT observations have demonstrated that detection is possible up to at least 230 GHz. This study offers a glimpse through the dense surrounding torus and into the innermost central region, where the jets are formed. This has enabled us to finally resolve this region and provide improved constraints on its expansion and magnetic field strength., Comment: 22 pages, 10 figures, published in A&A

Published
2025
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2. A multi-frequency study of sub-parsec jets with the Event Horizon Telescope

Author

Röder, Jan, Wielgus, Maciek, Lobanov, Andrei P., Krichbaum, Thomas P., Nair, Dhanya G., Lee, Sang-Sung, Ros, Eduardo, Fish, Vincent L., Blackburn, Lindy, Chan, Chi-kwan, Issaoun, Sara, Janssen, Michael, Johnson, Michael D., Doeleman, Sheperd S., Bower, Geoffrey C., Crew, Geoffrey B., Tilanus, Remo P. J., Savolainen, Tuomas, Impellizzeri, C. M. Violette, Alberdi, Antxon, Baczko, Anne-Kathrin, Gómez, José L., Lu, Ru-Sen, Paraschos, Georgios F., Traianou, Efthalia, Goddi, Ciriaco, Kim, Daewon, Lisakov, Mikhail, Kovalev, Yuri Y., Voitsik, Petr A., Sokolovsky, Kirill V., Akiyama, Kazunori, Albentosa-Ruíz, Ezequiel, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Bach, Uwe, Ball, David, Baloković, Mislav, Bandyopadhyay, Bidisha, Barrett, John, Bauböck, Michi, Benson, Bradford A., Bintley, Dan, Blundell, Raymond, Bouman, Katherine L., 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, 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., Cruz-Osorio, Alejandro, Cui, Yuzhu, Curd, Brandon, Dahale, Rohan, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Dhruv, Vedant, Dihingia, Indu K., Dougall, Sean Taylor, Dzib, Sergio A., Eatough, Ralph P., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fomalont, Edward, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, Gammie, Charles F., García, Roberto, Gentaz, Olivier, Georgiev, Boris, Gold, Roman, Gómez-Ruiz, Arturo I., 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, Inoue, Makoto, James, David J., Jannuzi, Buell T., Jeter, Britton, Jiang, Wu, Jiménez-Rosales, Alejandra, 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, Joana A., Kramer, Michael, Kuo, Cheng-Yu, La Bella, Noemi, Lauer, Tod R., Lee, Daeyoung, Leung, Po Kin, Levis, Aviad, Li, Zhiyuan, Lico, Rocco, Lindahl, Greg, Lindqvist, Michael, Liu, Jun, Liu, Kuo, Liuzzo, Elisabetta, Lo, Wen-Ping, Loinard, Laurent, Lonsdale, Colin J., Lowitz, Amy E., 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, Moscibrodzka, Monika, Mulaudzi, Wanga, Müller, Cornelia, Müller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Fuentes, Santiago Navarro, Neilsen, Joey, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A., Oh, Junghwan, Okino, Hiroki, Sánchez, Héctor R. Olivares, Ortiz-León, Gisela N., Oyama, Tomoaki, özel, Feryal, Palumbo, Daniel C. M., Park, Jongho, Parsons, Harriet, Patel, Nimesh, Pen, Ue-Li, Pesce, Dominic W., Piétu, Vincent, Plambeck, Richard, PopStefanija, Aleksandar, Porth, Oliver, Pötzl, Felix M., Prather, Ben, Preciado-López, Jorge A., Principe, Giacomo, Psaltis, Dimitrios, Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Ricarte, Angelo, Ripperda, Bart, Roelofs, Freek, Rogers, Alan, 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, 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, Stanway, Joshua S., Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Titus, Michael, Torne, Pablo, Toscano, Teresa, Trent, Tyler, Trippe, Sascha, Turk, Matthew, van Bemmel, Ilse, van Langevelde, Huib J., van Rossum, Daniel R., Vos, Jesse, Wagner, Jan, Ward-Thompson, Derek, Wardle, John, Washington, Jasmin E., Weintroub, Jonathan, Wharton, Robert, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, André, 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 - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230 GHz, leading to a number of unique studies on black holes and relativistic jets from active galactic nuclei (AGN). In total, eighteen sources were observed: the main science targets, Sgr A* and M87 along with various calibrators. We investigated the morphology of the sixteen AGN in the EHT 2017 data set, focusing on the properties of the VLBI cores: size, flux density, and brightness temperature. We studied their dependence on the observing frequency in order to compare it with the Blandford-K\"onigl (BK) jet model. We modeled the source structure of seven AGN in the EHT 2017 data set using linearly polarized circular Gaussian components and collected results for the other nine AGN from dedicated EHT publications, complemented by lower frequency data in the 2-86 GHz range. Then, we studied the dependences of the VLBI core flux density, size, and brightness temperature on the frequency measured in the AGN host frame. We compared the observations with the BK jet model and estimated the magnetic field strength dependence on the distance from the central black hole. Our results indicate a deviation from the standard BK model, particularly in the decrease of the brightness temperature with the observing frequency. Either bulk acceleration of the jet material, energy transfer from the magnetic field to the particles, or both are required to explain the observations.

Published
2025

3. Two-temperature treatments in magnetically arrested disk GRMHD simulations more accurately predict light curves of Sagittarius A*

Author

Salas, León, Liska, Matthew, Markoff, Sera, Chatterjee, Koushik, Musoke, Gibwa, Porth, Oliver, Ripperda, Bart, Yoon, Doosoo, and Mulaudzi, Wanga

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

The Event Horizon Telescope Collaboration (EHTC) observed the Galactic centre source Sgr A* and used emission models primarily based on single ion temperature (1T) general relativistic magnetohydrodynamic (GRMHD) simulations. This predicted emission is strongly dependent on a modelled prescription of the ion-to-electron temperature ratio. The two most promising models are magnetically arrested disk (MAD) states. However, these and nearly all MAD models exhibit greater light-curve variability at 230 GHz compared to historical observations. Moreover, no model successfully passes all the variability and multiwavelength constraints. This limitation possibly stems from the fact that the actual temperature ratio depends on microphysical dissipation, radiative processes and other effects not captured in ideal fluid simulations. Therefore, we investigate the effects of two-temperature (2T) thermodynamics in MAD GRMHD simulations of Sgr A*, where the temperatures of both species are evolved more self-consistently. We include Coulomb coupling, radiative cooling of electrons, and model heating via magnetic reconnection. We find that the light-curve variability more closely matches historical observations when we include the 2T treatment and variable adiabatic indices, compared to 1T simulations. Contrary to the common assumption of neglecting radiative cooling for the low accretion rates of Sgr A*, we also find that radiative cooling still affects the accretion flow, reducing the electron temperature in the inner disk by about 10%, which in turn lowers both the average flux and variability at 230 GHz by roughly 10%.

Published
2024

4. 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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5. MIGHTEE-HI: The first MeerKAT HI mass function from an untargeted interferometric survey

Author

Ponomareva, Anastasia A., Jarvis, Matt J., Pan, Hengxing, Maddox, Natasha, Jones, Michael G., Frank, Bradley S., Rajohnson, Sambatriniaina H. A., Mulaudzi, Wanga, Meyer, Martin, Adams, Elizabeth A. K., Baes, Maarten, Hess, Kelley M., Kurapati, Sushma, Prandoni, Isabella, Sinigaglia, Francesco, Spekkens, Kristine, Tudorache, Madalina, Heywood, Ian, Collier, Jordan D., and Sekhar, Srikrishna

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the first measurement of the HI mass function (HIMF) using data from MeerKAT, based on 276 direct detections from the MIGHTEE Survey Early Science data covering a period of approximately a billion years ($0 \leq z \leq 0.084 $). This is the first HIMF measured using interferometric data over non-group or cluster field, i.e. a deep blank field. We constrain the parameters of the Schechter function which describes the HIMF with two different methods: $1/\rm V_{\rm max}$ and Modified Maximum Likelihood (MML). We find a low-mass slope $\alpha=-1.29^{+0.37}_{-0.26}$, `knee' mass $\log_{10}(M_{*}/{\rm M_{\odot}}) = 10.07^{+0.24}_{-0.24}$ and normalisation $\log_{10}(\phi_{*}/\rm Mpc^{-3})=-2.34^{+0.32}_{-0.36}$ ($H_0 = 67.4$ kms$^{-1}$ Mpc$^{-1}$) for $1/\rm V_{\rm max}$ and $\alpha=-1.44^{+0.13}_{-0.10}$, `knee' mass $\log_{10}(M_{*}/{\rm M_{\odot}}) = 10.22^{+0.10}_{-0.13}$ and normalisation $\log_{10}(\phi_{*}/\rm Mpc^{-3})=-2.52^{+0.19}_{-0.14}$ for MML. When using $1/\rm V_{\rm max}$ we find both the low-mass slope and `knee' mass to be consistent within $1\sigma$ with previous studies based on single-dish surveys. The cosmological mass density of HI is found to be slightly larger than previously reported: $\Omega_{\rm HI}=5.46^{+0.94}_{-0.99} \times 10^{-4}h^{-1}_{67.4}$ from $1/\rm V_{\rm max}$ and $\Omega_{\rm HI}=6.31^{+0.31}_{-0.31} \times 10^{-4}h^{-1}_{67.4}$ from MML but consistent within the uncertainties. We find no evidence for evolution of the HIMF over the last billion years., Comment: 13 pages, 9 figures, accepted for publication in MNRAS

Published
2023
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6. Polarimetric Geometric Modeling for mm-VLBI Observations of Black Holes

Author

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

Published
2023
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7. MIGHTEE-H i: The first MeerKAT H i mass function from an untargeted interferometric survey

Author

Ponomareva, Anastasia A, primary, Jarvis, Matt J, additional, Pan, Hengxing, additional, Maddox, Natasha, additional, Jones, Michael G, additional, Frank, Bradley S, additional, Rajohnson, Sambatriniaina H A, additional, Mulaudzi, Wanga, additional, Meyer, Martin, additional, Adams, Elizabeth A K, additional, Baes, Maarten, additional, Hess, Kelley M, additional, Kurapati, Sushma, additional, Prandoni, Isabella, additional, Sinigaglia, Francesco, additional, Spekkens, Kristine, additional, Tudorache, Madalina, additional, Heywood, Ian, additional, Collier, Jordan D, additional, and Sekhar, Srikrishna, additional

Published
2023
Full Text
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8. Polarimetric Geometric Modeling for mm-VLBI Observations of Black Holes

Author

Roelofs, Freek, Johnson, Michael D., Chael, Andrew, Janssen, Michael, Wielgus, Maciek, Broderick, Avery E., 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, Broguiere, Dominique, Bronzwaer, Thomas, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E., Ceccobello, Chiara, 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, Dahale, Rohan, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Dhruv, Vedant, Doeleman, Sheperd S., Dougal, Sean, Dzib, Sergio A., Eatough, Ralph P., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, Gammie, Charles F., García, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, Gómez-Ruiz, Arturo I., Gómez, José L., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, 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, Jiang, Wu, Jiménez-Rosales, Alejandra, Jorstad, Svetlana, Joshi, Abhishek V., Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofuji, Yutaro, Koch, Patrick M., Koyama, Shoko, Kramer, Carsten, Kramer, Joana A., 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., Lowitz, Amy E., 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, Moscibrodzka, Monika, Mulaudzi, Wanga, Müller, Cornelia, Müller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, 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., Prather, Ben, Preciado-López, Jorge A., Psaltis, Dimitrios, Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Raymond, Alexander W., Rezzolla, Luciano, Ricarte, Angelo, Ripperda, Bart, Rogers, Alan, Romero-Cañizales, Cristina, Ros, Eduardo, 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, Sosapanta Salas, León David, Souccar, Kamal, Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Torne, Pablo, Toscano, Teresa, 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, Washington, Jasmin E., Weintroub, Jonathan, Wharton, Robert, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, André, Young, Ken, Younsi, Ziri, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, Zhao, Shan-Shan, Roelofs, Freek, Johnson, Michael D., Chael, Andrew, Janssen, Michael, Wielgus, Maciek, Broderick, Avery E., 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, Broguiere, Dominique, Bronzwaer, Thomas, Bustamante, Sandra, Byun, Do-Young, Carlstrom, John E., Ceccobello, Chiara, 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, Dahale, Rohan, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica, Desvignes, Gregory, Dexter, Jason, Dhruv, Vedant, Doeleman, Sheperd S., Dougal, Sean, Dzib, Sergio A., Eatough, Ralph P., Emami, Razieh, Falcke, Heino, Farah, Joseph, Fish, Vincent L., Fomalont, Ed, Ford, H. Alyson, Foschi, Marianna, Fraga-Encinas, Raquel, Freeman, William T., Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, Gammie, Charles F., García, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, Gómez-Ruiz, Arturo I., Gómez, José L., Gu, Minfeng, Gurwell, Mark, Hada, Kazuhiro, Haggard, Daryl, 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, Jiang, Wu, Jiménez-Rosales, Alejandra, Jorstad, Svetlana, Joshi, Abhishek V., Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Koay, Jun Yi, Kocherlakota, Prashant, Kofuji, Yutaro, Koch, Patrick M., Koyama, Shoko, Kramer, Carsten, Kramer, Joana A., 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., Lowitz, Amy E., 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, Moscibrodzka, Monika, Mulaudzi, Wanga, Müller, Cornelia, Müller, Hendrik, Mus, Alejandro, Musoke, Gibwa, Myserlis, Ioannis, Nadolski, Andrew, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, 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., Prather, Ben, Preciado-López, Jorge A., Psaltis, Dimitrios, Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark G., Raymond, Alexander W., Rezzolla, Luciano, Ricarte, Angelo, Ripperda, Bart, Rogers, Alan, Romero-Cañizales, Cristina, Ros, Eduardo, 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, Sosapanta Salas, León David, Souccar, Kamal, Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo P. J., Titus, Michael, Torne, Pablo, Toscano, Teresa, 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, Washington, Jasmin E., Weintroub, Jonathan, Wharton, Robert, Wiik, Kaj, Witzel, Gunther, Wondrak, Michael F., Wong, George N., Wu, Qingwen, Yadlapalli, Nitika, Yamaguchi, Paul, Yfantis, Aristomenis, Yoon, Doosoo, Young, André, Young, Ken, Younsi, Ziri, Yu, Wei, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhang, Shuo, Zhao, Guang-Yao, and Zhao, Shan-Shan

Abstract

The Event Horizon Telescope (EHT) is a millimeter very long baseline interferometry (VLBI) array that has imaged the apparent shadows of the supermassive black holes M87* and Sagittarius A*. Polarimetric data from these observations contain a wealth of information on the black hole and accretion flow properties. In this work, we develop polarimetric geometric modeling methods for mm-VLBI data, focusing on approaches that fit data products with differing degrees of invariance to broad classes of calibration errors. We establish a fitting procedure using a polarimetric “m-ring” model to approximate the image structure near a black hole. By fitting this model to synthetic EHT data from general relativistic magnetohydrodynamic models, we show that the linear and circular polarization structure can be successfully approximated with relatively few model parameters. We then fit this model to EHT observations of M87* taken in 2017. In total intensity and linear polarization, the m-ring fits are consistent with previous results from imaging methods. In circular polarization, the m-ring fits indicate the presence of event-horizon-scale circular polarization structure, with a persistent dipolar asymmetry and orientation across several days. The same structure was recovered independently of observing band, used data products, and model assumptions. Despite this broad agreement, imaging methods do not produce similarly consistent results. Our circular polarization results, which imposed additional assumptions on the source structure, should thus be interpreted with some caution. Polarimetric geometric modeling provides a useful and powerful method to constrain the properties of horizon-scale polarized emission, particularly for sparse arrays like the EHT.

Published
2023

9. The Galaxy Velocity Function from MIGHTEE-HI Early Science Data

Author

Mulaudzi, Wanga, Frank, Bradley, and Kraan-Korteweg, Renee Christine

Subjects
Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract

The velocity function of MIGHTEE-H I Early Science data is presented. This is the first velocity function that is based on a blind radio interferometric survey. As a precursor, understanding the systematics that affect the Early Science velocity function will optimise the full survey's analysis. PYMULTINEST and the Busy Function are employed to estimate the linewidths of the low spectral resolution data. The performance of PYMULTINEST in estimating known linewidths of simulated H I profiles with varying spectral resolution is assessed. The simulation study shows that the estimated linewidths of the Early Science data, using this novel method, are robust and are recovered within the uncertainty. The effects of cosmic variance, instrumental linewidth broadening and Doppler linewidth broadening on the velocity function are quantified within the context of the limitations of the Early Science data. The MIGHTEE-H I Early Science velocity function is compared with the velocity functions from previous large-scale H I surveys, namely the Arecibo Legacy Fast ALFA (ALFALFA) survey and the H I Parkes All-Sky Survey (HIPASS). There is general agreement with the ALFALFA and HIPASS results, when taking linewidth broadening into account, given that the MIGHTEE-H I Early Science data is strongly affected by cosmic variance. In particular, cosmic variance introduces an average uncertainty of ∼ 24% in the measured Early Science volume densities. The larger effective area of the full survey will reduce the impact of cosmic variance. The full survey velocity function can be further optimised by estimating the rotational velocities using kinematic modelling, and correcting the measured linewidths for instrumental broadening, Doppler broadening, turbulent motion and inclination effects.

Published
2022

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