A link between the H beta equivalent width, profile width, BLR size, and optical luminosity from a small sample of well-studied active galactic nuclei

We present diagrams of the relationship between the broad H beta emission-l ine parameters and the continuum luminosity obtained from a sample of 31 we ll-studied Seyfert 1.0-1.5 galaxies and quasars. The equivalent width of th e H beta line is inversely correlated with the continuum luminosity at 5100 Angstrom as EW similar to L-5100(-0.047+/-0.038), which seems to be compar able to that obtained by other authors for the Ly alpha. So, we have detect ed, although very marginally, a Baldwin effect in the H beta line. The rema rkably small scattering of the H beta equivalent widths probably indicates approximately the same spectral energy distribution from optics to ionizing radiation, nearly the same covering factor, and nearly isotropic continuum emission, although some of these agents can show small systematic changes with luminosity. The intrinsic Baldwin effect for the H beta is clearly see n only in NGC 5548. Considering the observed lag-luminosity and lag-line-wi dth dependences we suppose that it might be caused by full ionization of cl ouds. We compute the linear regression parameters (the slopes and intercept s) of the relationship between the H beta and optical continuum fluxes. In some cases, the regression parameters derived from the homogeneous data set s are significantly different for different observational periods. The lag of the H beta response to continuum variations shows a strong correlation w ith the luminosity. Combining the regression results on time delay and rms widths of the H beta line, we obtained the following mass-luminosity relati onship for AGNs: L proportional to M1.9+/-1.1.