Mapping feedback signatures in 3C 297: A quasar-host merger at Cosmic Noon

TL;DR

This study investigates the complex feedback processes in the quasar host galaxy 3C 297, revealing jet-driven outflows, star formation, and interactions between the AGN, jet, and interstellar medium during a galaxy merger at Cosmic Noon.

Contribution

It provides the first spatially-resolved analysis of ionized gas, star formation, and jet interactions in 3C 297, highlighting jet-induced feedback and merger-driven starburst activity.

Findings

Jet cocoon likely shocked the ISM, causing outflows.

AGN feedback dominates over radiation pressure.

Merger activity triggers star formation and gas outflows.

Abstract

We present a study of quasar host galaxy 3C 297 which is home to a powerful bent-jet radio source suggesting vigorous interaction with a dense ISM and/or jet precession. Archival HST imaging showed interestingly perturbed morphology of the host with a bright ~30 kpc arc feature, extended filamentary structure of line-emitting gas and clumpy blue excess emission co-spatial with the radio hotspots. Our VLT/SINFONI integral-field observations reveal complex, spatially-resolved H{\alpha}+[NII] emission in this source. A prominent blue-shifted wing in H{\alpha} indicates an ionized gas flow extending out to ~18 kpc from the nuclear region. Combining our SINFONI narrow-H{\alpha} data with archival HST/UV and VLA imaging, we map the young stellar population in the host and compare the spatial distribution of star-forming regions with the ionized gas motion and jet structure. In the attempt to characterize the feedback mechanisms in this chaotic system, we suggest that the powerful radio source dominates the feedback with possible contribution from radiation pressure due to AGN accretion. We also propose that the expanding jet cocoon likely shocked the ISM, triggering a kpc-scale ionized gas outflow and new starbursts that enhanced ongoing merger-induced star formation.