Powerful Radio Sources in the Southern Sky. IV. Observations of the G4Jy-3CRE Catalog with the Australian Square Kilometre Array Pathfinder

TL;DR

This paper presents ASKAP radio observations of the G4Jy-3CRE catalog, classifying source morphologies, identifying optical counterparts, and demonstrating improved resolution and sensitivity over previous surveys.

Contribution

It provides new ASKAP continuum imaging data for the G4Jy-3CRE catalog, enabling detailed morphological classification and optical identification of southern hemisphere radio sources.

Findings

Classified 66% of sources with jet morphologies

Identified optical counterparts for previously ambiguous sources

Classified FRI/FRII galaxies up to z=1.35

Abstract

A recent 2023 paper by Massaro et al. introduced the G4Jy-3CRE, a new catalog of the brightest radio sources in the southern hemisphere that serve as a southern equivalent to the Third Cambridge Catalog Revised (3CR). The G4Jy-3CRE catalog selected 264 sources from the GLEAM-4Jy survey based on the same criteria used to select the sources in the 3CR. In this paper, we present new Australian Square Kilometre Array Pathfinder (ASKAP) continuuum imaging of the G4Jy-3CRE catalog. We use the three most recent data releases from the Rapid ASKAP Continuum Survey (RACS), covering the sky south of +30{\deg}decl.: RACS-low1, RACS-mid, and RACS-high. Together, these data releases cover a range of frequencies from 600 to 1800 MHz. The RACS surveys have improved spatial resolution and sensitivity over archival surveys at the same frequency, enabling us to classify 173 sources (66% of the sample) with morphologies indicative of the presence of jets, 37 of which did not show jet activity on archival radio maps. We were able to effectively classify FRI/FRII galaxies up to a redshift of z = 1.35. Moreover, we identified six optical counterparts for sources that were either previously unidentified or ambiguous.