Spectropolarimetry of high-polarization Seyfert 1 galaxies

We have performed spectropolarimetry of fifteen high-polarization Seyfert 1 galaxies with the Lick 3 m and Keck 10 m telescopes. Our goals were to understand the geometry, kinematics, and nature of the polarization mechanisms of the BLR as well as its relationship with the large-scale morphological features of the host galaxy.; The broad H{dollar}beta{dollar} and H{dollar}alpha{dollar} profiles were analyzed in total flux F and polarized flux {dollar}Ptimes F{dollar}. We find that the dominant polarization mechanism in Seyfert 1 galaxies is reflection by dust with a substantial contribution from direct light. The narrow Balmer lines are less polarized than the broad Balmer lines.; The broad H{dollar}alpha{dollar} line profiles of seven galaxies were deblended into separate components, each characterized by its own polarization properties. The best results were obtained for the two objects with the highest S/N ratio, NGC 4151 and Mrk 231. We find that the motions of the gas in the BLR of NGC 4151 are strongly coupled to the dominant morphological features of the galaxy, in particular the central bar, the radio jet, the major plane, and the axis of rotation. We propose that NGC 4151 is the result of an old merger and that its BLR is not obscured. The BLR of Mrk 231 is dominated by ejection along its radio axis and its continuum is polarized by a tilted disk whose long axis is parallel to the axis joining the two nuclei. The BLR and continuum source of Mrk 231 are viewed almost entirely in scattered light with a small amount of direct light and are therefore likely obscured from our line-of-sight. Our results also indicate that the high-polarization wing components of the broad profiles of NGC 4151 and Mrk 231 probe regions closer to the central continuum source than the core components.; We confirm that the axis of small-scale radio emission tends to be offset by {dollar}sim 45spcirc{dollar} from the orientation of the most elongated morphological feature as projected on the sky. We suggest that this is a fundamental property of mergers and that a significant fraction of Seyfert 1 galaxies result from merger events.