We present gas kinematics based on the [OIII] $\lambda$5007 line and their connection to galaxy gravitational potential, active galactic nucleus (AGN) energetics, and star formation, using a large sample of ~110,000 AGNs and star-forming (SF) galaxies at z<0.3. Gas and stellar velocity dispersions are comparable to each other in SF galaxies, indicating that the ionized gas kinematics can be accounted by the gravitational potential of host galaxies. In contrast, AGNs clearly show non-gravitational kinematics, which is comparable to or stronger than the virial motion caused by the gravitational potential. The [OIII] velocity-velocity dispersion (VVD) diagram dramatically expands toward high values as a function of AGN luminosity, implying that the outflows are AGN-driven, while SF galaxies do not show such a trend. We find that the fraction of AGNs with a signature of outflow kinematics, steeply increases with AGN luminosity and Eddington ratio. In particular, the majority of luminous AGNs presents strong non-gravitational kinematics in the [OIII] profile. AGNs with strong outflow signatures show on average similar specific star formation rate (SSFR) to that of starforming galaxies. In contrast, AGNs with weak or no outflows have an order of magnitude lower SSFR, suggesting that AGNs with current strong outflows do now show any negative AGN feedback and that it may take dynamical time to impact on star formation over galactic scales.
J. Woo, D. Son and H. Bae
Thu, 23 Feb 17
Comments: ApJ submitted (revised based on the 2nd referee report), 13 pages, 11 figures