Spatially Resolved Kinematics of gas and stars in hidden type 1 AGNs

Abstract

We present the spatially resolved gas and stellar kinematics of a sample of ten hidden type 1 AGNs in order to investigate the true nature of the central source and the scaling relation with host galaxy stellar velocity dispersion. The sample is selected from a large number of hidden type 1 AGN, which are identified based on the presence of a broad component in the \ha\ line profile (i.e., full-width-at-half-maximum $>$ $\sim$1000 \kms), while they are often mis-classified as type 2 AGN because AGN continuum and broad emission lines are weak or obscured in the optical spectral range. We used the Blue Channel Spectrograph at the 6.5-m MMT (Multiple Mirror Telescope) to obtain long-slit data. We detected a broad \hb\ for only two targets, however, the presence of a strong broad \ha\ indicates that these AGNs are low-luminosity type 1 AGNs. We measured the velocity, velocity dispersion and flux of stellar continuum and gas emission lines (i.e., \hb\ and \oiii) as a function of distance from the center with a spatial scale of 0.3 arcsec pixel$^{-1}$. Spatially resolved gas kinematics traced by \hb\ or \oiii\ are generally similar to stellar kinematics except for the very center, where signatures of gas outflows are detected. We compare the luminosity-weighted effective stellar velocity dispersion with black hole mass, finding that these hidden type 1 AGN with relatively low back hole mass follow the scaling relation of the reverberation-mapped type 1 AGN and more massive inactive galaxies. }