First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
Kazunori Akiyama;Antxon Alberdi;Walter Alef;Keiichi Asada;Rebecca Azulay;Anne-Kathrin Baczko;David Ball;Mislav Baloković;John Barrett;Dan Bintley;Lindy Blackburn;Wilfred Boland;Katherine L. Bouman;Geoffrey C. Bower;Michael Bremer;Christiaan D. Brinkerink;Roger Brissenden;Silke Britzen;Avery E. Broderick;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;Pierre Christian;John E. Conway;James M. Cordes;Geoffrey B. Crew;Yuzhu Cui;Jordy Davelaar;Mariafelicia De Laurentis;Roger Deane;Jessica Dempsey;Gregory Desvignes;Jason Dexter;Sheperd S. Doeleman;Ralph P. Eatough;Heino Falcke;Vincent L. Fish;Ed Fomalont;Raquel Fraga-Encinas;Per Friberg;Christian M. Fromm;José L. Gómez;Peter Galison;Charles F. Gammie;Roberto García;Olivier Gentaz;Boris Georgiev;Ciriaco Goddi;Roman Gold;Minfeng Gu;Mark Gurwell;Kazuhiro Hada;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;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;Kuo Liu;Elisabetta Liuzzo;Wen-Ping Lo;Andrei P. Lobanov;Laurent Loinard;Colin Lonsdale;Ru-Sen Lu;Nicholas R. MacDonald;Jirong Mao;Sera Markoff;Daniel P. Marrone;Alan P. Marscher;Iván Martí-Vidal;Satoki Matsushita;Lynn D. Matthews;Lia Medeiros;Karl M. Menten;Yosuke Mizuno;Izumi Mizuno;James M. Moran;Kotaro Moriyama;Monika Moscibrodzka;Cornelia Müller;Hiroshi Nagai;Neil M. Nagar;Masanori Nakamura;Ramesh Narayan;Gopal Narayanan;Iniyan Natarajan;Roberto Neri;Chunchong Ni;Aristeidis Noutsos;Hiroki Okino;Héctor Olivares;Tomoaki Oyama;Feryal Özel;Daniel C. M. Palumbo;Nimesh Patel;Ue-Li Pen;Dominic W. Pesce;Vincent Piétu;Richard Plambeck;Aleksandar PopStefanija;Oliver Porth;Ben Prather;Jorge A. Preciado-López;Dimitrios Psaltis;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;Benjamin R. Ryan;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;Fumie Tazaki;Paul Tiede;Remo P. J. Tilanus;Michael Titus;Kenji Toma;Pablo Torne;Tyler Trent;Sascha Trippe;Shuichiro Tsuda;Ilse van Bemmel;Huib Jan van Langevelde;Daniel R. van Rossum;Jan Wagner;John Wardle;Jonathan Weintroub;Norbert Wex;Robert Wharton;Maciek Wielgus;George N. Wong;Qingwen Wu;André Young;Ken Young;Ziri Younsi;Feng Yuan;Ye-Fei Yuan;J. Anton Zensus;Guangyao Zhao;Shan-Shan Zhao;Ziyan Zhu;Joseph R. Farah;Zheng Meyer-Zhao;Daniel Michalik;Andrew Nadolski;Hiroaki Nishioka;Nicolas Pradel;Rurik A. Primiani;Kamal Souccar;Laura Vertatschitsch;Paul Yamaguchi
2019-01-01
Abstract
We present measurements of the properties of the central radio source in M87 using Event Horizon Telescope data obtained during the 2017 campaign. We develop and fit geometric crescent models (asymmetric rings with interior brightness depressions) using two independent sampling algorithms that consider distinct representations of the visibility data. We show that the crescent family of models is statistically preferred over other comparably complex geometric models that we explore. We calibrate the geometric model parameters using general relativistic magnetohydrodynamic (GRMHD) models of the emission region and estimate physical properties of the source. We further fit images generated from GRMHD models directly to the data. We compare the derived emission region and black hole parameters from these analyses with those recovered from reconstructed images. There is a remarkable consistency among all methods and data sets. We find that >50% of the total flux at arcsecond scales comes from near the horizon, and that the emission is dramatically suppressed interior to this region by a factor >10, providing direct evidence of the predicted shadow of a black hole. Across all methods, we measure a crescent diameter of 42 +/- 3 mu as and constrain its fractional width to be <0.5. Associating the crescent feature with the emission surrounding the black hole shadow, we infer an angular gravitational radius of GM/Dc(2) = 3.8 +/- 0.4 mu as. Folding in a distance measurement of 16.8(-0.7)(+0.8) gives a black hole mass of M = 6.5. 0.2 vertical bar(stat) +/- 0.7 vertical bar(sys) x 10(9) M-circle dot. This measurement from lensed emission near the event horizon is consistent with the presence of a central Kerr black hole, as predicted by the general theory of relativity.