The Variability of the Black-Hole Image in M87 at the Dynamical Time Scale
Creators: name: Satapathy, Kaushik
name: Psaltis, Dimitrios
name: Ozel, Feryal
name: Medeiros, Lia
name: Dougall, Sean T.
name: Chan, Chi-kwan
name: Wielgus, Maciek
name: Prather, Ben S.
name: Wong, George N.
name: Gammie, Charles F.
name: Akiyama, Kazunori
name: Alberdi, Antxon
name: Alef, Walter
name: Algaba, Juan Carlos
name: Anantua, Richard
name: Asada, Keiichi
name: Azulay, Rebecca
name: Baczko, Anne-Kathrin
name: Ball, David R.
name: Baloković, Mislav
name: Barrett, John
name: Benson, Bradford A.
name: Bintley, Dan
name: Blackburn, Lindy
name: Blundell, Raymond
name: Boland, Wilfred
name: Bouman, Katherine L.
name: Bower, Geoffrey C.
name: Boyce, Hope A.
name: Bremer, Michael
name: Brinkerink, Christiaan D.
name: Brissenden, Roger
name: Britzen, Silke
name: Broderick, Avery E.
name: Broguiere, Dominique
name: Bronzwaer, Thomas
name: Bustamente, Sandra
name: Byun, Do-Young
name: Carlstrom, John E.
name: Chael, Andrew
name: Chatterjee, Koushik
name: Chatterjee, Shami
name: Chen, Ming-Tang
name: Chen, Yongjun
name: Cho, Ilje
name: Christian, Pierre
name: Conway, John E.
name: Cordes, James M.
name: Crawford, Thomas
name: Crew, Geoffrey B.
name: Osorio, Alejandro Cruz
name: Cui, Yuzhu
name: Davelaar, Jordy
name: De Laurentis, Mariafelicia
name: Deane, Roger
name: Dempsey, Jessica T.
name: Desvignes, Gregory
name: Dexter, Jason
name: Doeleman, Sheperd S.
name: Eatough, Ralph
name: Falcke, Heino
name: Farah, Joseph R.
name: Fish, Vincent
name: Fomalont, Edward B.
name: Ford, H. Alyson
name: Fraga-Encinas, Raquel
name: Friberg, Per
name: Fromm, Christian M.
name: Fuentes, Antonio
name: Galison, Peter
name: García, Roberto
name: Gentaz, Olivier
name: Georgiev, Boris
name: Goddi, Ciriaco
name: Gold, Roman
name: Gomez-Ruiz, Arturo I.
name: Gómez, Jose L.
name: Gu, Minfeng
name: Gurwell, Mark A.
name: Hada, Kazuhiro
name: Haggard, Daryl
name: Hecht, Michael
name: Hesper, Ronald
name: Ho, Luis C.
name: Ho, Paul T.
name: Honma, Mareki
name: Huang, Chih-Wei L.
name: Huang, Lei
name: Hughes, David H.
name: Ikeda, Shiro
name: Inoue, Makoto
name: Issaoun, Sara
name: James, David J.
name: Jannuzi, Buell T.
name: Janssen, Michael
name: Jeter, Britton
name: Jiang, Wu
name: Rosales, Alejandra Jimenez
name: Johnson, Michael D.
name: Jorstad, Svetlana G.
name: Jung, Taehyun
name: Karami, Mansour
name: Karuppusamy, Ramesh
name: Kawashima, Tomohisa
name: Keating, Garrett K.
name: Kettenis, Mark
name: Kim, Dong-Jin
name: Kim, Jae-Young
name: Kim, Jongsoo
name: Kim, Junhan
name: Kino, Motoki
name: Koay, Jun Yi
name: Kofuji, Yutaro
name: Koch, Patrick M.
name: Koyama, Shoko
name: Kramer, Carsten
name: Kramer, Michael
name: Krichbaum, Thomas P.
name: Kuo, Cheng-Yu
name: Lauer, Tod R.
name: Lee, Sang-Sung
name: Levis, Aviad
name: Li, Yan-Rong
name: Li, Zhiyuan
name: Lindqvist, Michael
name: Lico, Rocco
name: Lindahl, Greg
name: Liu, Jun
name: Liu, Kuo
name: Liuzzo, Miss Elisabetta
name: Lo, Wen-Ping
name: Lobanov, Andrei
name: Loinard, Laurent
name: Lonsdale, Colin J.
name: Lu, Rusen
name: MacDonald, Nicholas R.
name: Mao, Jirong
name: Marchili, Nicola
name: Markoff, Sera
name: Marrone, Daniel
name: Marscher, Alan P.
name: Marti-Vidal, Ivan
name: Matsushita, Satoki
name: Matthews, Lynn
name: Menten, Karl M.
name: Mizuno, Izumi
name: Mizuno, Yosuke
name: Moran, James
name: Moriyama, Kotaro
name: Moscibrodzka, Monika
name: Muller, Cornelia
name: Mejias, Alejandro M.
name: Musoke, Gibwa
name: Nagai, Hiroshi
name: Nagar, Neil M.
name: Nakamura, Masanori
name: Narayan, Ramesh
name: Narayanan, Gopal
name: Natarajan, Iniyan
name: Nathanail, Antonios
name: Neilsen, Joey
name: Neri, Roberto
name: Ni, Chunchong
name: Noutsos, Aristeidis
name: Nowak, Michael A.
name: Okino, Hiroki
name: Olivares, Hector
name: Ortiz-Leon, Gisela N.
name: Oyama, Tomoaki
name: Palumbo, Daniel C.
name: Park, Jongho
name: Patel, Nimesh A.
name: Pen, Ue-Li
name: Pesce, Dominic W.
name: Pietu, Vincent
name: Plambeck, Richard L.
name: PopStefanija, Aleksandar
name: Porth, Oliver
name: Potzl, Felix
name: Preciado-López, Jorge A.
name: Pu, Hung-Yi
name: Ramakrishnan, Venkatessh
name: Rao, Ramprasad
name: Rawlings, Mark
name: Raymond, Alexander W.
name: Rezzolla, Luciano
name: Ripperda, Bart
name: Roelofs, Freek
name: Rogers, Alan E. E.
name: Ros, Eduardo
name: Rose, Mel
name: Roshanineshat, Arash
name: Rottmann, Helge
name: Roy, Alan L.
name: Ruszczyk, Chet
name: Rygl, Kazi
name: Sanchez, Salvador
name: Sanchez-Arguelles, David
name: Sasada, Mahito
name: Savolainen, Tuomas
name: Schloerb, F Peter
name: Schuster, Karl-Friedrich
name: Shao, Lijing
name: Shen, Zhi-Qiang
name: Small, Des
name: Sohn, Bong Won
name: SooHoo, Jason
name: Sun, He
name: Tazaki, Fumie
name: Tetarenko, Alexandra J.
name: Tiede, Paul
name: Tilanus, Remo
name: Titus, Michael
name: Toma, Kenji
name: Torne, Pablo
name: Traianou, E.
name: Trent, Tyler
name: Trippe, Sascha
name: van Bemmel, Ilse
name: van Langevelde, Huib Jan
name: van Rossum, Daniel R.
name: Wagner, Jan
name: Ward-Thompson, Derek
name: Wardle, John F.
name: Weintroub, Jonathan
name: Wex, Norbert
name: Wharton, Robert
name: Wiik, Kaj
name: Wu, Qingwen
name: Yoon, DooSoo
name: Young, Andre
name: Young, Ken H.
name: Younsi, Ziri
name: Yuan, Feng
name: Yuan, Ye-Fei
name: Zensus, J. Anton
name: Zhao, Guang-Yao
name: Zhao, Shan-Shan
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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.
description: Accepted for Publication in ApJ