New bright soft X-ray selected ROSAT AGN. II. Optical emission line properties

We present the emission line properties of a sample of 76 bright soft X-ray selected ROSAT Active Galactic Nuclei. All optical counterparts are Seyfert 1 galaxies with rather narrow permitted lines, strong optical FeII line blends, and weak forbidden lines. By selection, they also have steep soft X-ray spectra when compared with typical Seyfert 1 galaxies. We discuss possible origins of these peculiar trends employing detailed correlation analyses, including a Principal Component Analysis. The optical spectra are presented in the Appendix. Based in part on observations at the European Southern Observatory La Silla (Chile) with the 2.2m telescope of the Max-Planck-Society during MPG and ESO time. All spectra can be retrieved via CDS anonymous FTP 130.79.128.5.