南方基地知识库

Based on the gravitational red shift, which is a prediction of Einstein's general relativity theory, of broad optical emission lines in active galactic nuclei (AGNs), a new method is proposed to estimate the virial factors f in measuring black hole massesM(RM) by the reverberation mapping of AGNs. The factors f can be measured based on two physical quantities, i.e. the gravitational red shifts z(g) and the full widths at half maxima vFWHM of broad lines. In the past, it has been difficult to determine the factors f for individual AGNs. We apply this new method to several reverberation- mapped type 1 Seyfert galaxies. There is a correlation between f and the radius of the broad-line region (BLR) r(BLR), f = 5.4r(BLR)(0.3), for the gravitationally red-shifted broad lines He II, HeI, H beta and H alpha in the narrow-line type 1 Seyfert galaxy (NLS1) Mrk 110. This correlation results from the influence of the radiation pressure of the accretion disc on the BLR clouds. This influence seems to be more important than usually thought so in AGNs. Mrk 110 has f approximate to 8-16, distinctly larger than the mean (f) approximate to 1 usually used to estimate M-RM for v(FWHM.) NGC 4593 and NLS1 Mrk 486 have f approximate to 3 and f approximate to 9, respectively. Higher f values of several tens are derived for three other NLS1s. There is a correlation between f and accretion rate U-f=1, f = 6.8M(f= 1)(0.4) for five objects, where U-f=1 = M-center dot/L-Edd(c-2) as f = 1 is assumed when estimating MRM used in the Eddington luminosity L-Edd, M-center dot is the mass accretion rate, and c is the speed of light. These larger f values will produce higher MRM values and lower Eddington ratios.