The Supermassive Black Hole Masses of Reverberation-mapped Active Galactic Nuclei

Abstract

Using different kinds of velocity tracers derived from the broad H β  profile (in the mean or rms spectrum) and the corresponding virial factors f , the central supermassive black hole masses ( ) are calculated for a compiled sample of 120 reverberation-mapped (RM) active galactic nuclei (AGNs). For its subsample of RM AGNs with measured stellar velocity dispersion ( ), the multivariate linear regression technique is used to calibrate the mean value f , as well as the variable FWHM-based f . It is found that, whether excluding the pseudobulges or not, the from the H β  line dispersion in the mean spectrum ( ) has the smallest offset rms with respect to the relation. For the total sample excluding SDSS-RM AGNs, with respect to from or that from the H β  line dispersion in the rms spectrum ( ), it is found that we can obtain from the with the smallest offset rms of 0.38 or 0.23 dex, respectively. It implies that, with respect to the H β  FWHM, we prefer to calculate from the single-epoch spectrum. Using the FWHM-based f , we can improve the calculation from FWHM(H β ) and the mean f , with a decreased offset rms from 0.52 to 0.39 dex with respect to from for the subsample of 36 AGNs with . The value of 0.39 dex is almost the same as that from and the mean f .