The Shape of AGN-Driven Winds in the Seyfert Galaxy NGC 3516

Abstract: Active galactic nuclei (AGN) are known to drive ionized gas into their host galaxies, which may affect the evolution of both the central supermassive black holes and their hosts. In the case of NGC 3516, a nearby Seyfert 1 galaxy, these AGN winds have historically proven difficult to disentangle from galactic rotation. Using long slit spectroscopy at multiple position angles from the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Apache Point Observatory Kitt Peak Ohio State Multi Object Spectrograph, we separate these kinematic components by fitting multiple Gaussians to the H{\alpha}, N II, H{\beta}, and O III emission lines along the slits. We present a biconical outflow model that agrees well with the observed kinematics of the outflowing gas in the narrow-line region (NLR). Our results indicate that the structure of the O III emission is explained by dusty gas spirals in the galactic disk that are illuminated by the ionizing bicone, which is viewed along one edge, resulting in the complex nuclear kinematics. Our view into the bicone edge is consistent with the multiple, deep components of ionized absorption lines seen in UV and X-ray spectra of NGC 3516. The observed turnover in the velocity of the NLR clouds matches that from a simple dynamical model of radiative acceleration by the AGN and gravitational deceleration by the AGN and galaxy, indicating they are the principal forces at work on the gas clouds. Finally, the model launch radii indicate that the outflowing clouds originate primarily from the inner dusty spirals near the AGN.