Supermassive black holes in active galactic nuclei. II. Calibration of the black hole mass-velocity dispersion relationship for active galactic nuclei

We calibrate reverberation-based black hole (BH) masses in active galactic nuclei (AGNs) by using the correlation between BH mass, M_BH, and bulge/spheroid stellar velocity dispersion, σ*. We use new measurements of σ* for six AGNs and published velocity dispersions for 10 others, in conjunction with improved reverberation-mapping results, to determine the scaling factor required to bring reverberation-based BH masses into agreement with the quiescent galaxy M_BH-σ* relationship. The scatter in the AGN BH masses is found to be less than a factor of 3. The current observational uncertainties preclude the use of the scaling factor to discriminate between broad-line region models.