@inproceedings{0a71ae9ff1c64bdf912d6759efe5f4dc,
title = "The Black Hole Explorer: Photon Ring Science, Detection and Shape Measurement",
abstract = "General relativity predicts that black hole images ought to display a bright, thin (and as-of-yet-unresolved) ring. This “photon ring” is produced by photons that explore the strong gravity of the black hole, flowing along trajectories that experience extreme light bending within a few Schwarzschild radii of the horizon before escaping. The shape of the photon ring is largely insensitive to the precise details of the emission from the astronomical source surrounding the black hole and therefore provides a direct probe of the Kerr geometry and its parameters. The Black Hole Explorer (BHEX) is a proposed space-based experiment targeting the supermassive black holes M87* and Sgr A* with radio-interferometric observations at frequencies of 100 GHz through 300 GHz and from an orbital distance of ≲ 30,000 km. This design will enable measurements of the photon rings around both M87* and Sgr A*, confirming the Kerr nature of these sources and delivering sharp estimates of their masses and spins.",
keywords = "AGN, Black Hole, EHT, Interferometry, Photon Ring, Space Telescope, VLBI",
author = "Alexandru Lupsasca and Alejandro C{\'a}rdenas-Avenda{\~n}o and Palumbo, {Daniel C.M.} and Johnson, {Michael D.} and Gralla, {Samuel E.} and Marrone, {Daniel P.} and Peter Galison and Paul Tiede and Lennox Keeble",
note = "Publisher Copyright: {\textcopyright} 2024 SPIE.; Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave ; Conference date: 16-06-2024 Through 22-06-2024",
year = "2024",
doi = "10.1117/12.3019437",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Coyle, {Laura E.} and Shuji Matsuura and Perrin, {Marshall D.}",
booktitle = "Space Telescopes and Instrumentation 2024",
}