The properties of radio and mid-infrared detected galaxies and the effect of environment on the co-evolution of AGN and star formation at z ∼ 1

June 2020 • 2020MNRAS.494.5374S

Authors • Shen, Lu • Lemaux, Brian C. • Lubin, Lori M. • McKean, John • Miller, Neal A. • Pelliccia, Debora • Fassnacht, Christopher D. • Tomczak, Adam • Wu, Po-Feng • Kocevski, Dale • Gal, Roy • Hung, Denise • Squires, Gordon

Abstract • In this study, we investigate 179 radio-infrared (IR) galaxies drawn from a sample of spectroscopically confirmed galaxies, which are detected in radio and mid-IR (MIR) in the redshift range of 0.55 ≤ z ≤ 1.30 in the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. We constrain the active galactic nuclei (AGN) contribution to the total IR luminosity (f_AGN), and estimate the AGN luminosity (L_AGN) and the star formation rate (SFR). Based on the f_AGN and radio luminosity, radio-IR galaxies are split into galaxies that host either high- or low-f_AGN AGN (high-/low-f_AGN), and star-forming galaxies (SFGs) with little to no AGN activity. We study the properties of the three radio-IR sub-samples comparing to an underlying parent sample. In the comparison of radio luminosity of three sub-samples, no significant difference was found, which could be due to the combined contribution of radio emission from AGN and star formation. We find a positive relationship between L_AGN and specific SFR (sSFR) for both AGN sub-samples, strongly suggesting a co-evolution scenario of AGN and SF in these galaxies. A toy model is designed to demonstrate this co-evolution scenario, where we find that, in almost all cases, a rapid quenching time-scale is required, which we argue is a signature of AGN quenching. The environmental preference for intermediate/infall regions of clusters/groups remains across the co-evolution scenario, which suggests that galaxies might be in an orbital motion around the cluster/group during the scenario.

Links

• PREPRINT http://arxiv.org/abs/1911.00024
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2020MNRAS.494.5374S
• ELECTR https://doi.org/10.1093%2Fmnras%2Fstaa1005
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2020MNRAS.494.5374S
• PDF http://academic.oup.com/mnras/pdf-lookup/doi/10.1093/mnras/staa1005
• DATA http://archives.esac.esa.int/hsa/whsa/?ACTION=PUBLICATION&ID=2020MNRAS.494.5374S
• DATA https://irsa.ipac.caltech.edu/bibdata/2020/S/2020MNRAS.494.5374S.html