Akiyama, K;
Alberdi, A;
Alef, W;
Asada, K;
Azulay, R;
Baczko, A-K;
Ball, D;
... Yamaguchi, P; + view all
(2019)
First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole.
Astrophysical Journal Letters
, 875
(1)
, Article L6. 10.3847/2041-8213/ab1141.
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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 μas 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 μas. Folding in a distance measurement of ${16.8}_{-0.7}^{+0.8}\,\mathrm{Mpc}$ gives a black hole mass of $M=6.5\pm 0.2{| }_{\mathrm{stat}}\pm 0.7{| }_{\mathrm{sys}}\times {10}^{9}\hspace{2pt}{M}_{\odot }$. 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.
| Type: | Article |
|---|---|
| Title: | First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/2041-8213/ab1141 |
| Publisher version: | https://doi.org/10.3847/2041-8213/ab1141 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, black hole physics, galaxies: individual (M87), gravitation, techniques: high angular resolution, techniques: interferometric, DIFFERENTIAL EVOLUTION, GENETIC ALGORITHM, ACCRETION DISKS, INNER JET, RADIO JET, NUCLEUS, GALAXY, DISTRIBUTIONS, EMISSION, DISTANCE |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10073508 |
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