The supermassive black hole masses of reverberation-mapped active galactic nuclei

Using different kinds of velocity tracers derived from the broad H beta profile (in the mean or rms spectrum) and the corresponding virial factors f, the central supermassive black hole masses (M-BH) 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 (sigma(*)), 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 M-BH from the H beta line dispersion in the mean spectrum (sigma(H beta, mean)) has the smallest offset rms with respect to the M-BH-sigma(*) relation. For the total sample excluding SDSS-RM AGNs, with respect to M-BH from sigma(*) or that from the H beta line dispersion in the rms spectrum (sigma(H beta,rms)), it is found that we can obtain M-BH from the sigma(H beta), mean with the smallest offset rms of 0.38 or 0.23 dex, respectively. It implies that, with respect to the H beta FWHM, we prefer sigma(H beta), mean to calculate M-BH from the single-epoch spectrum. Using the FWHM-based f, we can improve the M-BH calculation from FWHM(H beta) and the mean f, with a decreased offset rms from 0.52 to 0.39 dex with respect to M-BH from sigma(*) for the subsample of 36 AGNs with sigma(*). The value of 0.39 dex is almost the same as that from sigma(H beta, mean) and the mean f.