Black hole masses of tidal disruption event host galaxies
  The mass of the central black hole in a galaxy that hosted a tidal disruption
event (TDE) is an important parameter in understanding its energetics and
dynamics. We present the first homogeneously measured black hole masses of a
complete sample of 12 optically/UV selected TDE host galaxies (down to
$g_{host}$$\leq$22 mag and $z$=0.37) in the Northern sky. The mass estimates
are based on velocity dispersion measurements, performed on late time optical
spectroscopic observations. We find black hole masses in the range
3$\times$10$^5$ M$_{\odot}$$\leq$M$_{\rm BH}$$\leq$2$\times$10$^7$ M$_{\odot}$.
The TDE host galaxy sample is dominated by low mass black holes ($\sim$10$^6$
M$_{\odot}$), as expected from theoretical predictions. The blackbody peak
luminosity of TDEs with M$_{\rm BH}$$\leq$10$^{7.1}$ M$_{\odot}$ is consistent
with the Eddington limit of the SMBH, whereas the two TDEs with M$_{\rm
BH}$$\geq$10$^{7.1}$ M$_{\odot}$ have peak luminosities below their SMBH
Eddington luminosity, in line with the theoretical expectation that the
fallback rate for M$_{\rm BH}$$\geq$10$^{7.1}$ M$_{\odot}$ is sub-Eddington. In
addition, our observations suggest that TDEs around lower mass black holes
evolve faster. These findings corroborate the standard TDE picture in 10$^6$
M$_{\odot}$ black holes. Our results imply an increased tension between
observational and theoretical TDE rates. By comparing the blackbody emission
radius with theoretical predictions, we conclude that the optical/UV emission
is produced in a region consistent with the stream self-intersection radius of
shallow encounters, ruling out a compact accretion disk as the direct origin of
the blackbody radiation at peak brightness.
