Published online by Cambridge University Press: 03 June 2010
A new empirical formulae is given for estimating the masses of black holes in AGNs from the Hβ velocity dispersion and the continuum luminosity at 5100 Å. It is calibrated to reverberation-mapping and stellar-dynamical estimates of black hole masses. The resulting mass estimates are as accurate as reverberation-mapping and stellar-dynamical estimates. The new mass estimates show that there is very little scatter in the MBH–Lbulge relationship for high-luminosity galaxies, and that the scatter increases substantially in lower-mass galaxies.