A Possible Detection of M31* with Chandra
نویسندگان
چکیده
Two independent sets of Chandra and HST images of the nuclear region of M31 allow registration of X-ray and optical images to ∼ 0.1. This registration shows that none of the bright (∼ 10erg s) X-ray sources near the nucleus is coincident with the central super-massive black hole, M31*. A 50ks Chandra HRC image shows 2.5σ evidence for a faint (3×10erg s), apparently resolved source which is consistent with the position of the M31*. The Bondi radius of M31* is 0.9, making it one of the few super-massive black holes with a resolvable accretion flow. This large radius and the previous detections of diffuse, X-ray emitting gas in the nuclear region make M31* one of the most secure cases for a radiatively inefficient accretion flow and place some of the most severe constraints on the radiative processes in such a flow. Subject headings: accretion — black hole physics — galaxies: individual (M31) — galaxies: nuclei
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