A Complete Sample of Soft X-Ray-selected AGNs. II. Statistical Analysis

Abstract

We present the optical spectra and simple statistical analysis for a complete sample of 110 soft X-ray–selected AGNs. About half of the sources are narrow-line Seyfert 1 galaxies (NLS1’s), which have the steepest X-ray spectra, the strongest Fe ii emission, and slightly weaker [O iii] k5007 emission than broad-line Seyfert 1’s (BLS1’s). Kolmogorov-Smirnov tests show that NLS1’s and BLS1’s have clearly different distributions of the X-ray spectral slope ?X, X-ray short-term variability, and Fe ii equivalent widths and luminosity and Fe ii/H? ratios. The differences in the [O iii]/H? and [O iii] equivalent widths are only marginal. We found no significant differences between NLS1’s and BLS1’s in their rest-frame 0.2–2.0 X-ray luminosities, rest-frame 5100 monochromatic luminosities, bolometric luminosities, redshifts, and their H? equivalent widths.