A TIDAL DISRUPTION EVENT IN A NEARBY GALAXY HOSTING AN INTERMEDIATE MASS BLACK HOLE

We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 keV flux declined by a factor of similar to 2300 over a time span of 6 yr, following a power-law decay with index similar to 2.44 +/- 0.40. The Chandra data alone vary by a factor of similar to 20. The spectrum is well fit by a blackbody with a constant temperature of kT similar to 0.09 keV (similar to 10(6) K). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the la level with the cluster (z = 0.062476). We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log(M-BH/M-O) similar to 5.5 +/- 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.