Deep spectroscopy of the MV ~-14.8 host galaxy of a tidal disruption flare in A1795

A likely tidal disruption of a star by the intermediate-mass black hole (IMBH) of a dwarf galaxy was recently identified in association with Abell 1795. Without deep spectroscopy for this very faint object, however, the possibility of a more massive background galaxy or even a disk-instability flare from a weak AGN could not be dismissed. We have now obtained 8 hours of Gemini spectroscopy which unambiguously demonstrate that the host galaxy is indeed an extremely low-mass (M⋆ � 3×10 8 M⊙) galaxy in Abell 1795, comparable to the least-massive galaxies determined to host IMBHs via other studies. We find that the spectrum is consistent with the X-ray flare being due to a tidal disruption event rather than an AGN flare. We also set improved limits on the black hole mass (log[M•/M⊙] � 5.3 5.7) and infer a 15-year X-ray variability of a factor of > 10 4 . The confirmation of this galaxy-black hole system provides a glimpse into a population of galaxies that is otherwise difficultto study, due to the galaxies’ low masses and intrinsic faintness, but which may be important contributors to the tidal disruption rate.