Universal Interferometric Signatures of a Black Hole's Photon Ring
Abstract
The Event Horizon Telescope image of the supermassive black hole in the galaxy M87 is dominated by a bright, unresolved ring. General relativity predicts that embedded within this image lies a thin "photon ring," which is composed of an infinite sequence of self-similar subrings that are indexed by the number of photon orbits around the black hole. The subrings approach the edge of the black hole "shadow," becoming exponentially narrower but weaker with increasing orbit number, with seemingly negligible contributions from high order subrings. Here, we show that these subrings produce strong and universal signatures on long interferometric baselines. These signatures offer the possibility of precise measurements of black hole mass and spin, as well as tests of general relativity, using only a sparse interferometric array.
Keywords
Cite
@article{arxiv.1907.04329,
title = {Universal Interferometric Signatures of a Black Hole's Photon Ring},
author = {Michael D. Johnson and Alexandru Lupsasca and Andrew Strominger and George N. Wong and Shahar Hadar and Daniel Kapec and Ramesh Narayan and Andrew Chael and Charles F. Gammie and Peter Galison and Daniel C. M. Palumbo and Sheperd S. Doeleman and Lindy Blackburn and Maciek Wielgus and Dominic W. Pesce and Joseph R. Farah and James M. Moran},
journal= {arXiv preprint arXiv:1907.04329},
year = {2020}
}
Comments
11 pages, 8 figures. Published in Science Advances