First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
Abstract
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 μ 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 μ as. Folding in a distance measurement of gives a black hole mass of . 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.
Funding
- National Science Foundation
- Smithsonian Institution
- U.S. Department of Energy
- National Aeronautics and Space Administration
- John Templeton Foundation
- Gordon and Betty Moore Foundation
- Harvard University
- University of Chicago
- University of Arizona
- Innovation, Science and Economic Development Canada
- Compute Canada
- Ministerio de Ciencia, Innovación y Universidades
- National Radio Astronomy Observatory
- Associated Universities
- International Max Planck Research School for Environmental, Cellular and Molecular Microbiology
- Government of Canada
- Leverhulme Trust
- National Research Foundation
- Department of Science and Technology, Ministry of Science and Technology, India
- Ministry of Education, Culture, Sports, Science and Technology
- National Natural Science Foundation of China
- Academia Sinica
- Chinese Academy of Sciences
- Consejo Nacional de Ciencia y Tecnología
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek
- Ministerio de Economía y Competitividad
- Generalitat Valenciana
- Nuclear Safety and Security Commission
- Korea Astronomy and Space Science Institute
- National Research Foundation of Korea
- Max-Planck-Gesellschaft
- Vetenskapsrådet
- China Scholarship Council
- European Southern Observatory
- Centre National de la Recherche Scientifique
- Universidad Nacional Autónoma de México
- National Astronomical Observatory of Japan
- Russian Science Foundation
- Ministero dello Sviluppo Economico
- Recruitment Program of Global Experts
- Istituto Nazionale di Fisica Nucleare
- Instituto de Astrofísica de Andalucía
- Institut Périmètre de physique théorique
- Toray Science Foundation
- National Nuclear Security Administration
- Natural Sciences and Engineering Research Council of Canada
- Japan Society for the Promotion of Science
- Comisión Nacional de Investigación Científica y Tecnológica
- Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México
- National Institutes of Natural Sciences
- National Key Research and Development Program of China
- Office of International Science and Engineering
- Los Alamos National Laboratory
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