X-ray evidence for ultra-fast outflows in local AGNs

TL;DR

This study provides comprehensive X-ray spectral analysis of local AGNs, revealing that ultra-fast outflows are common, highly ionized, and potentially influential in AGN feedback mechanisms, with velocities up to 0.3c.

Contribution

It offers the first large-sample statistical evidence of UFOs in local AGNs, detailing their velocities, ionization states, and potential role in feedback processes.

Findings

UFOs detected in over 40% of sources

Outflow velocities range from 0.03-0.3c

High ionization and large column densities observed

Abstract

X-ray evidence for ultra-fast outflows (UFOs) has been recently reported in a number of local AGNs through the detection of blue-shifted Fe XXV/XXVI absorption lines. We present the results of a comprehensive spectral analysis of a large sample of 42 local Seyferts and 5 Broad-Line Radio Galaxies (BLRGs) observed with XMM-Newton and Suzaku. We detect UFOs in >40% of the sources. Their outflow velocities are in the range 0.03-0.3c, with a mean value of ~0.14c. The ionization is high, in the range logxi~3-6 erg s^{-1} cm, and also the associated column densities are large, in the interval ~10^{22}-10^{24} cm^{-2}. Overall, these results point to the presence of highly ionized and massive outflowing material in the innermost regions of AGNs. Their variability and location on sub-pc scales favor a direct association with accretion disk winds/outflows. This also suggests that UFOs may potentially play a significant role in the AGN cosmological feedback besides jets and their study can provide important clues on the connection between accretion disks, winds and jets.