Tidal disruptions of stars by supermassive black holes

摘要

A dormant supermassive black hole lurking in the nucleus of a galaxy will be revealed when a star approaches close enough to be torn apart by tidal forces, and a flare of radiation is emitted as the stream of stellar debris falls back onto the black hole. The luminosity, temperature, and decay of a tidal disruption flare are dependent on the mass and spin of the central black hole, and can be used to directly probe dormant black holes in distant galaxies for which the sphere of influence of the black hole is unresolved, and a dynamical measurement on the black hole mass is not possible. Here we present the discovery of tidal disruption flares in the ultraviolet with the GALEX Deep Imaging Survey, and compare the properties of the flares to the theoretical predictions.