Zusammenfassung
We report the serendipitous discovery of a bright point source flare in the
Abell cluster 1795 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 years, 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 (~10^6 K). The flare is spatially coincident with the nuclear
region of a faint, inactive galaxy with a photometric redshift consistent at
the one sigma 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 with
log(M_BH/M_sun)~5.5+-0.5. If so, such a discovery indicates that tidal
disruption flares may be used to probe black holes in the intermediate mass
range, which are very difficult to study by other means.
Nutzer