Exploring the Fundamental Mechanism in Driving Highest-Velocity Ionized Outflows in Radio AGNs

Abstract

We investigate the ionized gas kinematics relationship with X-ray, radio and accreting properties using a sample of 348 nearby ((Formula presented.)) SDSS-FIRST-X-ray detected AGNs. X-ray properties of our sample are obtained from XMM-Newton, Swift and Chandra observations. We unveil the ionized gas outflows in our sample manifested by the non-gravitational broad component in [O iii]λ5007Å emission line profiles. From the comparison of the correlation of non-parametric outflow velocities (i.e., the velocity width, the maximal velocity of outflow and line dispersion) with X-ray luminosity and radio luminosity, we find that outflow velocities have similarly positive correlations with both X-ray and radio luminosity. After correcting for the gravitational component, we find that the [O iii] velocity dispersion normalized by stellar mass also increases with both X-ray luminosity and radio luminosity. We also find that, for a given X-ray (radio) luminosity, radio (X-ray) luminous AGNs have higher outflow velocities than non-radio (non-X-ray) luminous AGNs. Therefore, we find no clear preference between X-ray luminosity and radio luminosity in driving high-velocity ionized outflows and conclude that both AGN activity and small-scale jets contribute comparably. Moreover, there is no evidence that our obscured AGNs are preferentially associated with higher velocity outflows. Finally, we find a turning point around log (Formula presented.) when we explore the dependency of outflow velocity on Eddington ratio. It can be interpreted considering the role of high radiation pressure (log (Formula presented.)) in causing drastic reduction in the covering factor of the circumnuclear materials.