The Polarized Image of a Synchrotron Emitting Ring of Gas Orbiting a Black Hole
Creators: name: Narayan, Ramesh
name: Palumbo, Daniel C. M.
name: Johnson, Michael D.
name: Gelles, Zachary
name: Himwich, Elizabeth
name: Chang, Dominic O.
name: Ricarte, Angelo
name: Dexter, Jason
name: Gammie, Charles F.
name: Chael, Andrew A.
name: Collaboration, The Event Horizon Telescope
name: :
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
name: Balokovic, 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
name: Bremer, Michael
name: Brinkerink, Christiaan D.
name: Brissenden, Roger
name: Britzen, Silke
name: Broderick, Avery E.
name: Broguiere, Dominique
name: Bronzwaer, Thomas
name: Byun, Do-Young
name: Carlstrom, John E.
name: Chan, Chi-kwan
name: Chatterjee, Shami
name: Chatterjee, Koushik
name: Chen, Ming-Tang
name: Chen, Yongjun
name: Chesler, Paul M.
name: Cho, Ilje
name: Christian, Pierre
name: Conway, John E.
name: Cordes, James M.
name: Crawford, Thomas M.
name: Crew, Geoffrey B.
name: Cruz-Osorio, Alejandro
name: Cui, Yuzhu
name: Davelaar, Jordy
name: DeLaurentis, Mariafelicia
name: Deane, Roger
name: Dempsey, Jessica
name: Desvignes, Gregory
name: Doeleman, Sheperd S.
name: Eatough, Ralph P.
name: Falcke, Heino
name: Farah, Joseph
name: Fish, Vincent L.
name: Fomalont, Ed
name: Ford, H. Alyson
name: Fraga-Encinas, Raquel
name: Friberg, Per
name: Fromm, Christian M.
name: Fuentes, Antonio
name: Galison, Peter
name: Garcıa, Roberto
name: Gentaz, Olivier
name: Georgiev, Boris
name: Goddi, Ciriaco
name: Gold, Roman
name: Gomez, Jose L.
name: Gomez-Ruiz, Arturo I.
name: Gu, Minfeng
name: Gurwell, Mark
name: Hada, Kazuhiro
name: Haggard, Daryl
name: Hecht, Michael H.
name: Hesper, Ronald
name: Ho, Luis C.
name: Ho, Paul
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: Jimenez-Rosales, Alejandra
name: Jorstad, Svetlana
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, Michael
name: Kramer, Carsten
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, Elisabetta
name: Lo, Wen-Pin
name: Lobanov, Andrei P.
name: Loinard, Laurent
name: Lonsdale, Colin
name: Lu, Ru-Sen
name: MacDonald, Nicholas R.
name: Mao, Jirong
name: Marchili, Nicola
name: Markoff, Sera
name: Marrone, Daniel P.
name: Martı-Vidal, Alan P. Marscher Ivan
name: Matsushita, Satoki
name: Matthews, Lynn D.
name: Medeiros, Lia
name: Menten, Karl M.
name: Mizuno, Izumi
name: Mizuno, Yosuke
name: Moran, James M.
name: Moriyama, Kotaro
name: Moscibrodzka, Monika
name: Muller, Cornelia
name: Musoke, Gibwa
name: Mejıas, Alejandro Mus
name: Nagai, Hiroshi
name: Nagar, Neil M.
name: Nakamura, Masanori
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: Ozel, Feryal
name: Park, Jongho
name: Patel, Nimesh
name: Pen, Ue-Li
name: Pesce, Dominic W.
name: Pietu, Vincent
name: Plambeck, Richard
name: PopStefanija, Aleksandar
name: Porth, Oliver
name: Potzl, Felix M.
name: Prather, Ben
name: Preciado-Lopez, Jorge A.
name: Psaltis, Dimitrios
name: Pu, Hung-Yi
name: Ramakrishnan, Venkatessh
name: Rao, Ramprasad
name: Rawlings, Mark G.
name: Raymond, Alexander W.
name: Rezzolla, Luciano
name: Ripperda, Bart
name: Roelofs, Freek
name: Rogers, Alan
name: Ros, Eduardo
name: Rose, Mel
name: Roshanineshat, Arash
name: Rottmann, Helge
name: Roy, Alan L.
name: Ruszczyk, Chet
name: Rygl, Kazi L. J.
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, Zhiqiang
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 P. J.
name: Titus, Michael
name: Toma, Kenji
name: Torne, Pablo
name: Trent, Tyler
name: Traianou, Efthalia
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
name: Weintroub, Jonathan
name: Wex, Norbert
name: Wharton, Robert
name: Wielgus, Maciek
name: Wong, George N.
name: Wu, Qingwen
name: Yoon, Doosoo
name: Young, Andre
name: Young, Ken
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: 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.
description: 29 pages, 11 figures, published in ApJ on May 3