Narrow-line seyfert 1 galaxies and the MBH-σ relation

We have studied the location of narrow-line Seyfert 1 ( NLS1) galaxies and broad-line Seyfert 1 (BLS1) galaxies on the M-BH-sigma relation of nonactive galaxies. We find that NLS1 galaxies as a class-as well as the BLS1 galaxies of our comparison sample-do follow the M-BH-sigma relation of nonactive galaxies if we use the width of the [S II] lambda lambda 6716, 6731 emission lines as a surrogate for stellar velocity dispersion, sigma*. We also find that the width of [O III] lambda 5007 is a good surrogate for sigma*, but only after (1) removal of asymmetric blue wings and, more importantly, after (2) excluding core [O III] lines with strong blueshifts (i. e., excluding galaxies which have their [O III] velocity fields dominated by radial motions, presumably outflows). The same galaxies which are extreme outliers in [ O III] still follow the M-BH-sigma relation in [S II]. We systematically investigate the influence of several parameters on the NSL1 galaxies' location on the M-BH-sigma plane: [O III] blueshift, L/L-Edd, intensity ratio Fe II/H beta, NLR density, and absolute magnitude. Implications for NLS1 models and for their evolution along the M-BH-sigma tion are discussed.