Significant Suppression of Star Formation in Radio-Quiet AGN Host Galaxies with Kiloparsec-Scale Radio Structures

TL;DR

This study reveals that radio-quiet AGN with kiloparsec-scale radio structures can significantly suppress star formation in their host galaxies, primarily through radiative outflows interacting with the interstellar medium.

Contribution

It demonstrates that star formation suppression in these AGN hosts is more likely caused by radiative outflows rather than small-scale radio jets, based on energetics analysis.

Findings

11 AGN show kiloparsec-scale radio structures inconsistent with star formation.

Most radio structures are too small to drive star formation suppression via jets.

Radiative outflows have sufficient energy to suppress star formation in most cases.

Abstract

We conducted 22~GHz 1" JVLA imaging of 100 radio-quiet X-ray selected AGN from the Swift-BAT survey. We find AGN-driven kiloparsec-scale radio structures inconsistent with pure star formation in 11 AGN. The host galaxies of these AGN lie significantly below the star-forming main sequence, indicating suppressed star formation. While these radio structures tend to be physically small compared to the host galaxy, the global star formation rate of the host is affected. We evaluate the energetics of the radio structures interpreted first as immature radio jets, and then as consequences of an AGN-driven radiative outflow, and compare them to two criteria for successful feedback: the ability to remove the CO-derived molecular gas mass from the galaxy gravitational potential and the kinetic energy transfer to molecular clouds leading to $v_\mathrm{cloud} > \sigma_*$. In most cases, the jet interpretation is insufficient to provide the energy necessary to cause the star formation suppression. Conversely, the wind interpretation provides ample energy in all but one case. We conclude that it is more likely that the observed suppression of star formation in the global host galaxy is due to ISM interactions of a radiative outflow, rather than a small-scale radio jet.