AGNIFS survey of local AGN : GMOS-IFU data and outflows in 30 sources

Abstract

We analyse optical data cubes of the inner kiloparsec of 30 local (z ≤ 0.02) active galactic nucleus (AGN) hosts that our research group, AGNIFS, has collected over the past decade via observations with the integral field units of the Gemini Multi-Object Spectrographs. Spatial resolutions range between 50 and 300 pc and spectral coverage is from 4800 or 5600 to 7000 Å, at velocity resolutions of ≈50 km s−1. We derive maps of the gas excitation and kinematics, and determine the AGN ionization axis – which has random orientation relative to the galaxy – and the kinematic major axes of the emitting gas. We find that rotation dominates the gas kinematics in most cases, but is disturbed by the presence of inflows and outflows. Outflows have been found in 21 nuclei, usually along the ionization axis. The gas velocity dispersion is traced by W80 (velocity width encompassing 80 per cent of the line flux), adopted as a tracer of outflows. In seven sources, W80 is enhanced perpendicularly to the ionization axis, indicating lateral expansion of the outflow. We have estimated mass-outflow rates M˙ and powers E˙, finding median values of log [M/˙ ( M yr−1)] = −2.1+1.6 −1.0 and log [E/˙ ( erg s−1)] = 38.5+1.8 −0.9, respectively. Both quantities show a mild correlation with the AGN luminosity (LAGN). E˙ is of the order of 0.01 LAGN for four sources, but much lower for the majority (nine) of the sources, with a median value of log [E/L AGN] = −5.34+3.2 −0.9, indicating that typical outflows in the local Universe are unlikely to significantly impact their host galaxy evolution.