Title | First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multiwavelength Observations, Data Processing, and Calibration |
Authors | Akiyama, Kazunori Alberdi, Antxon Alef, Walter Algaba, Juan Carlos Anantua, Richard Asada, Keiichi Azulay, Rebecca Bach, Uwe Baczko, Anne-Kathrin Ball, David Balokovic, Mislav Barrett, John Baubock, Michi Benson, Bradford A. Bintley, Dan Blackburn, Lindy Blundell, Raymond Bouman, Katherine L. Bower, Geoffrey C. Boyce, Hope Bremer, Michael Brinkerink, Christiaan D. Brissenden, Roger Britzen, Silke Broderick, Avery E. Broguiere, Dominique Bronzwaer, Thomas Bustamante, Sandra Byun, Do-Young Carlstrom, John E. Ceccobello, Chiara Chael, Andrew Chan, Chi-kwan Chatterjee, Koushik Chatterjee, Shami Chen, Ming-Tang Chen, Yongjun Cheng, Xiaopeng Cho, Ilje Christian, Pierre Conroy, Nicholas S. Conway, John E. Cordes, James M. Crawford, Thomas M. Crew, Geoffrey B. Cruz-Osorio, Alejandro Cui, Yuzhu Davelaar, Jordy De Laurentis, Mariafelicia Deane, Roger Dempsey, Jessica Desvignes, Gregory Dexter, Jason Dhruv, Vedant Doeleman, Sheperd S. Dougal, Sean Dzib, Sergio A. Eatough, Ralph P. Emami, Razieh Falcke, Heino Farah, Joseph Fish, Vincent L. Fomalont, Ed Ford, H. Alyson Fraga-Encinas, Raquel Freeman, William T. Friberg, Per Fromm, Christian M. Fuentes, Antonio Galison, Peter Gammie, Charles F. Garcia, Roberto Gentaz, Olivier Georgiev, Boris Goddi, Ciriaco Gold, Roman Gomez-Ruiz, Arturo, I Gomez, Jose L. Gu, Minfeng Gurwell, Mark Hada, Kazuhiro Haggard, Daryl Haworth, Kari Hecht, Michael H. Hesper, Ronald Heumann, Dirk Ho, Luis C. Ho, Paul Honma, Mareki Huang, Chih-Wei L. Huang, Lei Hughes, David H. Ikeda, Shiro Impellizzeri, C. M. Violette Inoue, Makoto Issaoun, Sara James, David J. Jannuzi, Buell T. Janssen, Michael Jeter, Britton Jiang, Wu Jimenez-Rosales, Alejandra Johnson, Michael D. Jorstad, Svetlana Joshi, Abhishek, V Jung, Taehyun Karami, Mansour Karuppusamy, Ramesh Kawashima, Tomohisa Keating, Garrett K. Kettenis, Mark Kim, Dong-Jin Kim, Jae-Young Kim, Jongsoo Kim, Junhan Kino, Motoki Koay, Jun Yi Kocherlakota, Prashant Kofuji, Yutaro Koch, Patrick M. Koyama, Shoko Kramer, Carsten Kramer, Michael Krichbaum, Thomas P. Kuo, Cheng-Yu La Bella, Noemi Lauer, Tod R. Lee, Daeyoung Lee, Sang-Sung Leung, Po Kin Levis, Aviad Li, Zhiyuan Lico, Rocco Lindahl, Greg Lindqvist, Michael Lisakov, Mikhail Liu, Jun Liu, Kuo Liuzzo, Elisabetta Lo, Wen-Ping Lobanov, Andrei P. Loinard, Laurent Lonsdale, Colin J. Lu, Ru-Sen Mao, Jirong Marchili, Nicola Markoff, Sera Marrone, Daniel P. Marscher, Alan P. Marti-Vidal, Ivan Matsushita, Satoki Matthews, Lynn D. Medeiros, Lia Menten, Karl M. Michalik, Daniel Mizuno, Izumi Mizuno, Yosuke Moran, James M. Moriyama, Kotaro Moscibrodzka, Monika Muller, Cornelia Mus, Alejandro Musoke, Gibwa Myserlis, Ioannis Nadolski, Andrew Nagai, Hiroshi Nagar, Neil M. Nakamura, Masanori Narayan, Ramesh Narayanan, Gopal Natarajan, Iniyan Nathanail, Antonios Fuentes, Santiago Navarro Neilsen, Joey Neri, Roberto Ni, Chunchong Noutsos, Aristeidis Nowak, Michael A. Oh, Junghwan Okino, Hiroki Olivares, Hector Ortiz-Leon, Gisela N. Oyama, Tomoaki Palumbo, Daniel C. M. Paraschos, Georgios Filippos Park, Jongho Parsons, Harriet Patel, Nimesh Pen, Ue-Li Pesce, Dominic W. Pietu, Vincent Plambeck, Richard PopStefanija, Aleksandar Porth, Oliver Potzl, Felix M. Prather, Ben Preciado-Lopez, Jorge A. Pu, Hung-Yi Ramakrishnan, Venkatessh Rao, Ramprasad Rawlings, Mark G. Raymond, Alexander W. Rezzolla, Luciano Ricarte, Angelo Ripperda, Bart Roelofs, Freek Rogers, Alan Ros, Eduardo Romero-Canizales, Cristina Roshanineshat, Arash Rottmann, Helge Roy, Alan L. Ruiz, Ignacio Ruszczyk, Chet Rygl, Kazi L. J. Sanchez, Salvador Sanchez-Arguelles, David Sanchez-Portal, Miguel Sasada, Mahito Satapathy, Kaushik Savolainen, Tuomas Schloerb, F. Peter Schonfeld, Jonathan Schuster, Karl-Friedrich Shao, Lijing Shen, Zhiqiang Small, Des Sohn, Bong Won SooHoo, Jason Souccar, Kamal Sun, He Tazaki, Fumie Tetarenko, Alexandra J. Tiede, Paul Tilanus, Remo P. J. Titus, Michael Torne, Pablo Traianou, Efthalia Trent, Tyler Trippe, Sascha Turk, Matthew van Bemmel, Ilse van Langevelde, Huib Jan van Rossum, Daniel R. Vos, Jesse Wagner, Jan Ward-Thompson, Derek Wardle, John Weintroub, Jonathan Wex, Norbert Wharton, Robert Wielgus, Maciek Wiik, Kaj Witzel, Gunther Wondrak, Michael F. Wong, George N. Wu, Qingwen Yamaguchi, Paul Yoon, Doosoo Young, Andre Young, Ken Younsi, Ziri Yuan, Feng Yuan, Ye-Fei Zensus, J. Anton Zhang, Shuo Zhao, Guang-Yao Zhao, Shan-Shan Agurto, Claudio Araneda, Juan Pablo Arriagada, Oriel Bertarini, Alessandra Berthold, Ryan Blanchard, Jay Brown, Ken Cardenas, Mauricio Cantzler, Michael Caro, Patricio Chuter, Tim C. Ciechanowicz, Miroslaw Coulson, Iain M. Crowley, Joseph Degenaar, Nathalie Dornbusch, Sven Duran, Carlos A. Forster, Karl Geertsema, Gertie Gonzalez, Edouard Graham, Dave Gueth, Frederic Han, Chih-Chiang Herrera, Cristian Herrero-Illana, Ruben Heyminck, Stefan Hoge, James Huang, Yau-De Jiang, Homin John, David Klein, Thomas Kubo, Derek Kuroda, John Kwon, Caleb Laing, Robert Liu, Ching-Tang Liu, Kuan-Yu Mac-Auliffe, Felipe Martin-Cocher, Pierre Matulonis, Callie Messias, Hugo Meyer-Zhao, Zheng Montenegro-Montes, Francisco Montgomerie, William Muders, Dirk Nishioka, Hiroaki Norton, Timothy J. Olivares, Rodrigo Perez-Beaupuits, Juan Pablo Parra, Rodrigo Poirier, Michael Pradel, Nicolas Raffin, Philippe A. Ramirez, Jorge Reynolds, Mark Saez-Madain, Alejandro F. Santana, Jorge Silva, Kevin M. Sousa, Don Stahm, William Torstensson, Karl Venegas, Paulina Walther, Craig Wieching, Gundolf Wijnands, Rudy Wouterloot, Jan G. A. |
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Ctr Astron & Astrophys, 52 Hillhouse Ave, New Haven, CT 06511 USA Univ Illinois, Dept Phys, 1110 West Green St, Urbana, IL 61801 USA Fermilab Natl Accelerator Lab, MS209,POB 500, Batavia, MS 60510 USA Univ Chicago, Dept Astron & Astrophys, 5640 South Ellis Ave, Chicago, IL 60637 USA East Asian Observ, 660 N Aohoku Pl, Hilo, HI 96720 USA James Clerk Maxwell Telescope JCMT, 660 N Aohoku Pl, Hilo, HI 96720 USA CALTECH, 1200 East Calif Blvd, Pasadena, CA 91125 USA Acad Sinica, Inst Astron & Astrophys, 645 N Aohoku Pl, Hilo, HI 96720 USA Univ Hawaii Manoa, Dept Phys & Astron, 2505 Correa Rd, Honolulu, HI 96822 USA McGill Univ, Dept Phys, 3600 Rue Univ, Montreal, PQ H3A 2T8, Canada McGill Univ, McGill Space Inst, 3550 Rue Univ, Montreal, PQ H3A 2A7, Canada Inst Radioastron Millimetr IRAM, 300 Rue Piscine, F-38406 St Martin Dheres, France Radboud Univ Nijmegen, Inst Math Astrophys & Particle Phys IMAPP, Dept Astrophys, POB 9010, NL-6500 GL Nijmegen, Netherlands Perimeter Inst Theoret Phys, 31 Caroline St N, Waterloo, ON N2L 2Y5, Canada Univ Waterloo, Dept Phys & Astron, 200 Univ Ave, Waterloo, ON N2L 3G1, Canada Univ Waterloo, Waterloo Ctr Astrophys, Waterloo, ON N2L 3G1, Canada Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA Korea Astron & Space Sci Inst, Daedeok Daero 776, Daejeon 34055, South Korea Univ Sci & Technol, Gajeong Ro 217, Daejeon 34113, South Korea Univ Chicago, Kavli Inst Cosmol Phys, 5640 South Ellis Ave, Chicago, IL 60637 USA Univ Chicago, Dept Phys, 5720 South Ellis Ave, Chicago, IL 60637 USA Univ Chicago, Enrico Fermi Inst, 5640 South Ellis Ave, Chicago, IL 60637 USA Chalmers Univ Technol, Dept Space Earth & Environm, Onsala Space Observ, SE-43992 Onsala, Sweden Princeton Univ, Princeton Ctr Theoret Sci, Jadwin Hall, Princeton, NJ 08544 USA NASA Hubble Fellowship Program, Washington, DC USA Univ Arizona, Data Sci Inst, 1230 N Cherry Ave, Tucson, AZ 85721 USA Univ Arizona, Program Appl Math, 617 N Santa Rita, Tucson, AZ 85721 USA Cornell Univ, 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Phys, Wuhan 430074, Hubei, Peoples R China Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England Univ Chinese Acad Sci, Sch Astron & Space Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China Univ Sci & Technol China, Astron Dept, Hefei 230026, Peoples R China Bard Coll, 30 Campus Rd, Annandale On Hudson, NY 12504 USA European Southern Observ, Alonso de Cordova 3107,Casilla 19001, Santiago, Chile Univ Bonn, Inst Geodesy & Geoinformat, D-53113 Bonn, Germany Natl Radio Astron Observ, Socorro, NM 87801 USA CALTECH, Space Radiat Lab, 1200 East Calif Blvd, Pasadena, CA 91125 USA Royal Netherlands Meteorol Inst, Res & Dev Weather & Climate Models, Utrechtseweg 297, NL-3731 GA De Bilt, Netherlands Joint ALMA Observ, Alonso de Cordova 3107, Vitacura 7630355, Santiago De Chi, Chile SKA Observ, Jodrell Bank, Macclesfield SK11 9FT, Cheshire, England European Southern Observ, Karl Schwarzschild Str 2, D-85478 Garching, Germany Univ Space Res Assoc, NASA Ames Res Ctr, SOFIA Sci Ctr, Moffett Field, CA 94035 USA Pontificia Univ Catolica Chile, Ctr Astroingn AIUC, Av Vicuna Mackena 4860, Santiago, Chile Univ Michigan, Dept Astron, 1085 South Univ Ave, Ann Arbor, MI 48109 USA NRAO Technol Ctr, Natl Radio Astron Observ, 1180 Boxwood Estate Rd, Charlottesville, VA 22903 USA |
Keywords | SUPERMASSIVE BLACK-HOLE GALACTIC-CENTER MAGNETAR GHZ VLBI OBSERVATIONS SCATTER-BROADENED IMAGE RAY FLARING PROPERTIES COMPACT RADIO-SOURCE PARSEC-SCALE JET X-RAY INTRINSIC SIZE ACCRETION FLOW |
Issue Date | 1-May-2022 |
Publisher | ASTROPHYSICAL JOURNAL LETTERS |
Abstract | We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5-11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of similar to 50 mu as, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*'s broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior. |
URI | http://hdl.handle.net/20.500.11897/643349 |
ISSN | 2041-8205 |
DOI | 10.3847/2041-8213/ac6675 |
Indexed | SCI(E) |
Appears in Collections: | 物理学院 科维理天文与天体物理研究所 |