First M87 Event Horizon Telescope Results: The Shadow and Mass of the Central Black Hole
Abstract
In this talk I will describe the Event Horizon Telescope (EHT) modeling procedures, their application to the M87 data, and our resulting constraints on the source structure and black hole mass. EHT imaging of the radio source in M87 has revealed an asymmetric ring-like structure with a diameter of approximately 40 microarcseconds. Motivated by these image reconstructions, we have developed and fit a flexible class of geometric models to the interferometric data products. The resulting fits demonstrate that the 2017 observations of M87 are well-described by a horizon-scale crescent structure. We have further developed procedures for fitting the M87 data with synthetic data generated from a large library of general relativistic magnetohydrodynamic (GRMHD) simulations, finding that while stochastic turbulence structures prevent any individual simulated image from providing a good fit to the data, we are nevertheless able to quantify the statistical consistency of the M87 data with the GRMHD models. We find that the emission region parameters derived from these analyses are consistent both with one another and with those obtained from the image reconstructions. Associating the crescent feature from the geometric models with the anticipated lensed emission seen in the GRMHD simulations, we measure an angular size for the gravitational radius of the black hole of 3.8 ± 0.4 microarcseconds. Combined with independent distance estimates, the resulting constraint on the black hole mass is 6.5 ± 0.7 billion solar masses.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23542905P