Black hole mass and velocity dispersion of narrow line region in active galactic nuclei and narrow line Seyfert 1 galaxies

Abstract

Controversy regarding whether Narrow Line Seyfert 1 galaxies (NLS1s) follow the same black hole - galactic bulge relation as normal galaxies has been raised by Mathur et al. (2001) and Ferrarese et al. (2001). In this paper, the correlation between the black hole mass and the velocity dispersion of the narrow line region, indicated by the [OIII] line width for a heterogeneous sample of NLS1s, is examined. We show that the non-virial component subtracted [OIII] width, which may well represent the stellar velocity dispersion (σ), correlates with the estimated black hole mass MBH, made using the empirical law for the size of the broad line region from the reverberation mapping measurements. Considering measurement errors, we find that the relation between MBH and the [OIII] width in active galactic nuclei (both NLS1s in this paper and normal Seyferts in Nelson 2000) is consistent with that defined in nearby hot galaxies (ellipticals and spiral bulge) but with more scatter. It seems that there is no clear difference in the relation between MBH and σ (represented by the [OIII] width for AGN) in both NLS1s and normal broad line active galactic nuclei from the same relation defined by nearby hot galaxies.