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

Kaushik Satapathy , Dimitrios Psaltis , Feryal Özel , Lia Medeiros , Sean T. Dougall , Chi-Kwan Chan , Maciek Wielgus , Ben S. Prather , George N. Wong , Charles F. Gammie , Kazunori Akiyama , Antxon Alberdi , Walter Alef , Juan Carlos Algaba , Richard Anantua , Keiichi Asada , Rebecca Azulay , Anne-Kathrin Baczko , David Ball , Mislav Baloković , John Barrett , Bradford A. Benson , Dan Bintley , Lindy Blackburn , Raymond Blundell , Wilfred Boland , Katherine L. Bouman , Geoffrey C. Bower , Hope Boyce , Michael Bremer , Christiaan D. Brinkerink , Roger Brissenden , Silke Britzen , Avery E. Broderick , Dominique Broguiere , Thomas Bronzwaer , Sandra Bustamente , Do-Young Byun , John E. Carlstrom , Andrew Chael , Koushik Chatterjee , Shami Chatterjee , Ming-Tang Chen , Yongjun Chen , Ilje Cho , Pierre Christian , John E. Conway , James M. Cordes , Thomas M. Crawford , Geoffrey B. Crew , Alejandro Cruz-Osorio , Yuzhu Cui , Jordy Davelaar , Mariafelicia de Laurentis , Roger Deane , Jessica Dempsey , Gregory Desvignes (1) , Jason Dexter , Sheperd S. Doeleman , Ralph P. Eatough , Heino Falcke , Joseph Farah , Vincent L. Fish , Ed Fomalont , H. Alyson Ford , Raquel Fraga-Encinas , Per Friberg , Christian M. Fromm , Antonio Fuentes , Peter Galison , Roberto García , Olivier Gentaz , Boris Georgiev , Ciriaco Goddi , Roman Gold , Arturo I. Gómez-Ruiz , José L. Gómez , Minfeng Gu , Mark Gurwell , Kazuhiro Hada , Daryl Haggard , Michael H. Hecht , Ronald Hesper , Luis C. Ho , Paul Ho , Mareki Honma , Chih-Wei L. Huang , Lei Huang , David H. Hughes , Shiro Ikeda , Makoto Inoue , Sara Issaoun , David J. James , Buell T. Jannuzi , Michael Janssen , Britton Jeter , Wu Jiang , Alejandra Jimenez-Rosales , Michael D. Johnson , Svetlana Jorstad , Taehyun Jung , Mansour Karami , Ramesh Karuppusamy , Tomohisa Kawashima , Garrett K. Keating , Mark Kettenis , Dong-Jin Kim , Jae-Young Kim , Jongsoo Kim , Junhan Kim , Motoki Kino , Jun Yi Koay , Yutaro Kofuji , Patrick M. Koch , Shoko Koyama , Carsten Kramer , Michael Kramer , Thomas P. Krichbaum , Cheng-Yu Kuo , Tod R. Lauer , Sang-Sung Lee , Aviad Levis , Yan-Rong Li , Zhiyuan Li , Michael Lindqvist , Rocco Lico , Greg Lindahl , Jun Liu , Kuo Liu , Elisabetta Liuzzo , Wen-Ping Lo , Andrei P. Lobanov , Laurent Loinard , Colin Lonsdale , Ru-Sen Lu , Nicholas R. Macdonald , Jirong Mao , Nicola Marchili , Sera Markoff , Daniel P. Marrone , Alan P. Marscher , Iván Martí-Vidal , Satoki Matsushita , Lynn D. Matthews , Karl M. Menten , Izumi Mizuno , Yosuke Mizuno , James M. Moran , Kotaro Moriyama , Monika Moscibrodzka , Cornelia Müller , Alejandro Mus Mejías , Gibwa Musoke , Hiroshi Nagai , Neil M. Nagar , Masanori Nakamura , Ramesh Narayan , Gopal Narayanan , Iniyan Natarajan , Antonios Nathanail , Joey Neilsen , Roberto Neri , Chunchong Ni , Aristeidis Noutsos , Michael A. Nowak , Hiroki Okino , Héctor Olivares , Gisela N. Ortiz-León , Tomoaki Oyama , Daniel C. M. Palumbo , Jongho Park , Nimesh Patel , Ue-Li Pen , Dominic W. Pesce , Vincent Piétu , Richard Plambeck , Aleksandar Popstefanija , Oliver Porth , Felix M. Pötzl , Jorge A. Preciado-López , Hung-Yi Pu , Venkatessh Ramakrishnan , Ramprasad Rao , Mark G. Rawlings , Alexander W. Raymond , Luciano Rezzolla , Bart Ripperda , Freek Roelofs , Alan Rogers , Eduardo Ros , Mel Rose , Arash Roshanineshat , Helge Rottmann , Alan L. Roy , Chet Ruszczyk , Kazi L. J. Rygl , Salvador Sánchez , David Sánchez-Arguelles , Mahito Sasada , Tuomas Savolainen , F. Peter Schloerb , Karl-Friedrich Schuster , Lijing Shao , Zhiqiang Shen , Des Small , Bong Won Sohn , Jason Soohoo , He Sun , Fumie Tazaki , Alexandra J. Tetarenko , Paul Tiede , Remo P. J. Tilanus , Michael Titus , Kenji Toma , Pablo Torne , Efthalia Traianou , Tyler Trent , Sascha Trippe , Ilse van Bemmel , Huib Jan van Langevelde , Daniel R. van Rossum , Jan Wagner , Derek Ward-Thompson , John Wardle , Jonathan Weintroub , Norbert Wex , Robert Wharton , Kaj Wiik , Qingwen Wu , Doosoo Yoon , André Young , Ken Young , Ziri Younsi , Feng Yuan , Ye-Fei Yuan , J. Anton Zensus , Guang-Yao Zhao , Shan-Shan Zhao

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics

The black hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center of the M87 galaxy, this timescale (5-61 days) is comparable to the 6 day extent of the 2017 EHT observations. Closure phases along baseline triangles are robust interferometric observables that are sensitive to the expected structural changes of the images but are free of station-based atmospheric and instrumental errors. We explored the day-to-day variability in closure-phase measurements on all six linearly independent nontrivial baseline triangles that can be formed from the 2017 observations. We showed that three triangles exhibit very low day-to-day variability, with a dispersion of ~3°-5°. The only triangles that exhibit substantially higher variability (~90°-180°) are the ones with baselines that cross the visibility amplitude minima on the u-v plane, as expected from theoretical modeling. We used two sets of general relativistic magnetohydrodynamic simulations to explore the dependence of the predicted variability on various black hole and accretion-flow parameters. We found that changing the magnetic field configuration, electron temperature model, or black hole spin has a marginal effect on the model consistency with the observed level of variability. On the other hand, the most discriminating image characteristic of models is the fractional width of the bright ring of emission. Models that best reproduce the observed small level of variability are characterized by thin ring-like images with structures dominated by gravitational lensing effects and thus least affected by turbulence in the accreting plasmas.

Keywords: 159; 739; Astrophysics - High Energy Astrophysical Phenomena

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

Kaushik Satapathy, Dimitrios Psaltis, Feryal Özel, Lia Medeiros, Sean T. Dougall, et al.. The Variability of the Black Hole Image in M87 at the Dynamical Timescale. The Astrophysical Journal, 2022, 925, ⟨10.3847/1538-4357/ac332e⟩. ⟨insu-03713346⟩