Powerful Activity in the Bright Ages. I. A Visible/IR Survey of High Redshift 3C Radio Galaxies and Quasars

TL;DR

This study provides high-quality UV and visible images of 22 high-redshift 3C radio galaxies and QSOs, revealing active star formation, distorted morphologies, and optical-radio axis alignments, enhancing understanding of galaxy evolution.

Contribution

It introduces a new data reduction strategy for HST WFC3 images and offers detailed morphological and photometric analysis of high-redshift radio-loud AGN.

Findings

UV emission suggests active star formation

Distorted host galaxy morphologies observed

Brighter QSOs tend to be redder

Abstract

We present new rest frame UV and visible observations of 22 high-redshift (1 < z < 2.5) 3C radio galaxies and QSOs obtained with the Hubble Space Telescope's (HST) Wide Field Camera 3 (WFC3) instrument. Using a custom data reduction strategy in order to assure the removal of cosmic rays, persistence signal, and other data artifacts, we have produced high-quality science-ready images of the targets and their local environments. We observe targets with regions of UV emission suggestive of active star formation. In addition, several targets exhibit highly distorted host galaxy morphologies in the rest frame visible images. Photometric analyses reveals that brighter QSOs tend to be generally redder than their dimmer counterparts. Using emission line fluxes from the literature, we estimate that emission line contamination is relatively small in the rest frame UV images for the QSOs. Using archival VLA data, we have also created radio map overlays for each of our targets, allowing for analysis of the optical and radio axes alignment.