Evidence for AGN-driven Outflows in Young Radio Quasars

TL;DR

This study provides evidence that young radio quasars exhibit broad emission lines indicative of powerful outflows likely driven by jets, highlighting AGN feedback processes in early galaxy evolution.

Contribution

It presents near-infrared spectra of young radio quasars showing exceptionally broad [O III] lines, supporting jet-induced outflows as a key AGN feedback mechanism.

Findings

Broad [O III] lines with FWHM 1300-2100 km/s observed

Black hole masses estimated at 10^8.9-10^9.7 solar masses

Host galaxies have stellar masses around 10^11.3-10^12.2 solar masses

Abstract

We present near-infrared spectra of young radio quasars [P(1.4GHz) ~ 26-27 W/Hz] selected from the Wide-Field Infrared Survey Explorer. The detected objects have typical redshifts of z ~ 1.6-2.5 and bolometric luminosities ~ 10^47 erg/s. Based on the intensity ratios of narrow emission lines, we find that these objects are mainly powered by active galactic nuclei (AGNs), although star formation contribution cannot be completely ruled out. The host galaxies experience moderate levels of extinction, A(V) ~ 0-1.3 mag. The observed [O III] luminosities and rest-frame J-band magnitudes constrain the black hole masses to lie in the range ~ 10^8.9-10^9.7 solar mass. From the empirical correlation between black hole mass and host galaxy mass, we infer stellar masses of ~ 10^11.3-10^12.2 solar mass. The [O III] line is exceptionally broad, with full width at half maximum ~1300 to 2100 km/s, significantly larger than that of ordinary distant quasars. We argue that these large line widths can be explained by jet-induced outflows, as predicted by theoretical models of AGN feedback.