2011ApJ...738...68P

We divide a sample of 302 type-1 active galactic nuclei into two subsamples based on the narrow-line [O III]/Hβ_NLRratio, expecting that there will be a stronger starburst (H II region) contribution to the narrow-line emission for R = log([O III]/Hβ_NLR) < 0.5. For both samples, we find significant differences in correlations between spectral properties of objects with R < 0.5 and R > 0.5. We find similar differences when we divide the sample based on the FWHM ratios of [O III] and broad Hβ lines (R₁ = log (FWHM [O III]/FWHM Hβ_broad)^>_<- 0.8), i.e., similar correlations between R > 0.5 and R₁< -0.8 subsamples from one side and R < 0.5 and R₁> -0.8 subsamples from the other side. The most interesting difference is in the correlation between the broad Hβ FWHM and luminosity in the R < 0.5 (R₁> -0.8) sample, which indicates a connection between the broad-line region kinematics and the photoionization source. We discuss possible effects that can cause these differences in spectral properties of two subsamples.