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 2300 over a time span of 6 yr, following a power-law decay with index 2.44 ± 0.40. The Chandra data alone vary by a factor of 20. The spectrum is well fit by a blackbody with a constant temperature of kT 0.09 keV (10⁶ K). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1σ 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) 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.