Probing the interplay between jets, winds and multi-phase gas in 11 radio-quiet PG Quasars: A uGMRT-VLA study

TL;DR

This study uses high-resolution radio observations to investigate the presence and properties of jets and magnetic fields in 11 radio-quiet PG quasars, revealing low-power jets and complex magnetic field structures with implications for AGN feedback.

Contribution

First detailed polarization and morphology study of radio-quiet PG quasars combining VLA and uGMRT data, highlighting jet presence and magnetic field configurations.

Findings

Low-power jets detected in 9 out of 11 quasars.

Linear polarization observed in 4 sources with fractional polarization up to 21%.

No strong correlation between radio properties and galaxy star formation or emission line data.

Abstract

We present polarization-sensitive images from the Karl G. Jansky Very Large Array (VLA) at 5 GHz of 11 radio-quiet PG quasars. Based on the radio morphology, spectral index and polarization properties from the VLA study, coupled with the findings of our previous 685 MHz uGMRT data, we find the presence of low-power jets on sub-arcsecond and arcsecond scales in 9 sources; some show signatures of bent jets. The origin of radio emission remains unclear in the remaining 2 sources. Of the 11 sources, linear polarization is detected in four of them with fractional polarization ranging between 2% and 21%. In PG 1229+204, the inferred B-field direction is parallel to the local kpc-scale jet direction. The inferred B-fields are transverse to the weak southward extension in PG 0934+013. For PG 0050+124 and PG 0923+129, the relationship between the B-field structure and radio outflow direction remains unclear. Localized or small-scale jet-medium interactions can be inferred across the sample based on the VLA jet kinetic power arguments and polarization data. These may have the potential as a feedback mechanism. We find that the radio properties do not show strong correlations with the star formation, [O III] and CO quantities published in the literature. The lack of evidence of AGN feedback on the global galaxy properties could be due to the relative time scales of AGN activity and those over which any impact might be taking place.