Gravitational Test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole

• DOI: 10.1103/physrevlett.125.141104
• Publication Date: 2020-10-01T17:01:13Z
• Authors: Dimitrios Psaltis; Lia Medeiros; Pierre Christian; Feryal Özel; Kazunori Akiyama; Antxon Alberdi; Walter Alef; Keiichi Asada; Rebecca Azulay; David Ball; Mislav Baloković; John Barrett; Dan Bintley; Lindy Blackburn; Wilfred Boland; Geoffrey C. Bower; Michael Bremer; Christiaan D. Bri...; Roger Brissenden; Silke Britzen; Dominique Broguiere; Thomas Bronzwaer; Do-Young Byun; John E. Carlstrom; Andrew Chael; Chi-kwan Chan; Shami Chatterjee; Koushik Chatterjee; Ming-Tang Chen; Yongjun Chen; Ilje Cho; John E. Conway; James M. Cordes; Geoffrey B. Crew; Yuzhu Cui; Jordy Davelaar; Mariafelicia De L...; Roger Deane; Jessica Dempsey; Gregory Desvignes; Jason Dexter; Ralph P. Eatough; Heino Falcke; Vincent L. Fish; Ed Fomalont; Raquel Fraga-Encinas; Per Friberg; Christian M. Fromm; Charles F. Gammie; Roberto García; Olivier Gentaz; Ciriaco Goddi; José L. Gómez; Minfeng Gu; Mark Gurwell; Kazuhiro Hada; Ronald Hesper; Luis C. Ho; Paul Ho; Mareki Honma; Chih-Wei L. Huang; Lei Huang; David H. Hughes; Makoto Inoue; Sara Issaoun; David J. James; Buell T. Jannuzi; Michael Janssen; Wu Jiang; Alejandra Jimenez...; Michael D. Johnson; Svetlana Jorstad; Taehyun Jung; Mansour Karami; Ramesh Karuppusamy; Tomohisa Kawashima; Garrett K. Keating; Mark Kettenis; Jae-Young Kim; Junhan Kim; Jongsoo Kim; Motoki Kino; Jun Yi Koay; Patrick M. Koch; Shoko Koyama; Michael Kramer; Carsten Kramer; Thomas P. Krichbaum; Cheng-Yu Kuo; Tod R. Lauer; Sang-Sung Lee; Yan-Rong Li; Zhiyuan Li; Michael Lindqvist; Rocco Lico; Jun Liu; Kuo Liu; Elisabetta Liuzzo; Wen-Ping Lo; Andrei P. Lobanov; Colin Lonsdale; Ru-Sen Lu; Jirong Mao; Sera Markoff; Daniel P. Marrone; Alan P. Marscher; Iván Martí-Vidal; Satoki Matsushita; Yosuke Mizuno; Izumi Mizuno; James M. Moran; Kotaro Moriyama; Monika Moscibrodzka; Cornelia Müller; Gibwa Musoke; Alejandro Mus Mejías; Hiroshi Nagai; Neil M. Nagar; Ramesh Narayan; Gopal Narayanan; Iniyan Natarajan; Roberto Neri; Aristeidis Noutsos; Hiroki Okino; Héctor Olivares; Tomoaki Oyama; Daniel C. M. Palumbo; Jongho Park; Nimesh Patel; Ue-Li Pen; Vincent Piétu; Richard Plambeck; Aleksandar PopSte...; Ben Prather; Jorge A. Preciado...; Venkatessh Ramakr...; Ramprasad Rao; Mark G. Rawlings; Alexander W. Raymond; Bart Ripperda; Freek Roelofs; Alan Rogers; Eduardo Ros; Mel Rose; Arash Roshanineshat; Helge Rottmann; Alan L. Roy; Chet Ruszczyk; Benjamin R. Ryan; Kazi L. J. Rygl; Salvador Sánchez; David Sánchez-Arg...; Mahito Sasada; Tuomas Savolainen; F. Peter Schloerb; Karl-Friedrich Sc...; Lijing Shao; Zhiqiang Shen; Des Small; Bong Won Sohn; Jason SooHoo; Fumie Tazaki; Remo P. J. Tilanus; Michael Titus; Pablo Torne; Tyler Trent; Efthalia Traianou; Sascha Trippe; Ilse van Bemmel; Huib Jan van Lang...; Daniel R. van Rossum; Jan Wagner; John Wardle; Derek Ward-Thompson; Jonathan Weintroub; Norbert Wex; Robert Wharton; Maciek Wielgus; George N. Wong; Qingwen Wu; Doosoo Yoon; André Young; Ken Young; Ziri Younsi; Feng Yuan; Ye-Fei Yuan; Shan-Shan Zhao
• Keywords: 330; Astronomy; M87; Mathematical sciences; FOS: Physical sciences; General Relativity and Quantum Cosmology (gr-qc); Gravitation and Astrophysics; 530; 01 natural sciences; General Relativity and Quantum Cosmology; Gravitational waves; Stellar-mass sources; Event Horizon Telescope (EHT); Engineering; 0103 physical sciences; High Energy Astrophysical Phenomena (astro-ph.HE); Multidisciplinary; Science & Technology; ta115; [PHYS.GRQC] Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]; Physics; 4. Education; EHT collaboration; 500; General physics; 001; 16. Peace & justice; Physical sciences; Physical Sciences; [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]; [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph]; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; Astrophysics - High Energy Astrophysical Phenomena

The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements. We use numerical calculations of regular, parametric, non-Kerr metrics to identify the common characteristic among these different parametrizations that control the predicted shadow size. We show that the shadow-size measurements place significant constraints on deviation parameters that control the second post-Newtonian and higher orders of each metric and are, therefore, inaccessible to weak-field tests. The new constraints are complementary to those imposed by observations of gravitational waves from stellar-mass sources.<br/>Physical Review Letters<br/>