Radio Properties of the BAT AGN: the FIR-Radio Relation, the Fundamental Plane, and the Main Sequence of Star Formation

TL;DR

This study uses high-resolution JVLA imaging to analyze radio properties of 70 radio-quiet AGN, confirming the FIR-radio relation and exploring the origins of radio emission, with implications for star formation and AGN activity.

Contribution

It provides detailed radio morphology classifications and compares core and extended emissions with models, advancing understanding of radio emission origins in radio-quiet AGN.

Findings

FIR-radio relation holds after removing AGN contribution.

Radio emission consistent with coronal and jet models.

AGN below the main sequence tend to have core or jet-like radio morphologies.

Abstract

We have conducted 22 GHz 1" JVLA imaging of 70 radio-quiet AGN from the Swift-BAT survey. We find radio cores in all but three objects. The radio morphologies of the sample fall into three groups: compact and core-dominated, extended, and jet-like. We spatially decompose each image into core flux and extended flux, and compare the extended radio emission to that predicted from previous Herschel observations using the canonical FIR-radio relation. After removing the AGN contribution to the FIR and radio flux densities, we find that the relation holds remarkably well despite the potentially different star formation physics in the circumnuclear environment. We also compare our core radio flux densities with predictions of coronal models and scale-invariant jet models for the origin of radio emission in radio-quiet AGN, and find general consistency with both models. However, we find that the $L_{\mathrm{R}} / L_{\mathrm{X}}$ relation does not distinguish between star formation and non-relativistic AGN-driven outflows as the origin of radio emission in radio-quiet AGN. Finally, we examine where objects with different radio morphologies fall in relation to the main sequence of star formation, and conclude that those AGN that fall below the main sequence, as X-ray selected AGN have been found to do, have core-dominated or jet-like 22 GHz morphologies.