A Revised Calibration of the Virial Mass Estimator for Black Holes in
  Active Galaxies Based on Single-epoch H$\beta$ Spectra
  The masses of supermassive black holes in broad-line active galactic nuclei
(AGNs) can be measured through reverberation mapping, but this method currently
cannot be applied to very large samples or to high-redshift AGNs. As a
practical alternative, one can devise empirical scaling relations, based on the
correlation between broad-line region size and AGN luminosity and the relation
between black hole mass and bulge stellar velocity dispersion, to estimate the
virial masses of black holes from single-epoch spectroscopy. We present a
revised calibration of the black hole mass estimator for the commonly used
H$\beta$ emission line. Our new calibration takes into account the recent
determination of the virial coefficient for pseudo and classical bulges.
