Weighing the black hole in active galactic nuclei

Black hole masses of AGNs are usually derived from two correlations: one between the black hole mass and the central velocity dispersion and one between the broad line region size and the optical continuum luminosity. Besides applying them in deriving black hole masses of some AGNs, we employed the fundamental plane of elliptical galaxies to estimate the central velocity dispersions of AGN host galaxies and then the black hole masses of AGNs. We also derived another empirical relation between the BLR size and H,3 emission line luminosity and argued that more accurate black hole masses of extremely radio-loud AGNs could be obtained with it than the usual R-L-5100Angstrom relation.Physics, MultidisciplinarySCI(E)CPCI-S(ISTP)