Co-evolution of AGN and Star-forming Galaxies in the Australia Telescope Large Area Survey

TL;DR

This study uses the ATLAS radio survey to explore the relationship between active galactic nuclei and star-forming galaxies, revealing unexpected findings about galaxy types and their evolution at high redshifts.

Contribution

It provides new insights into the co-evolution of AGN and star-forming galaxies using a comprehensive multi-wavelength radio survey, highlighting unexpected galaxy types and behaviors.

Findings

Discovery of FRI/FRII radio-loud AGN in spiral galaxies

Identification of radio-bright AGN faint in infrared, possibly high redshift

Detection of IR-luminous radio-quiet AGN affecting radio-infrared ratios

Abstract

ATLAS (Australia Telescope Large Area Survey) is a wide deep radio survey which is distinguished by its comprehensive multi-wavelength approach. ATLAS is creating a large dataset of radio-selected galaxies for studying the evolution and inter-relationship of star-forming and active galaxies. Although the project is far from complete, we are already starting to answer some of these questions, and have stumbled across three surprises along the way: * FRI/FRII radio-loud AGN embedded within spiral galaxies, * radio-bright AGN which are unexpectedly faint in the infrared, and which may be at high redshift * IR-luminous radio-quiet AGN which are partly responsible for the wide variations in reported values of the radio-infrared ratio These and other observations suggest that the AGN activity and star formation become increasingly inter-dependent at high redshifts.