The Properties of Radio and Mid-infrared Detected Galaxies and the
  Effect of Environment on the Co-evolution of AGN and Star Formation at $z
  \sim 1$
  In this study we investigate 179 radio-IR galaxies drawn from a sample of
spectroscopically-confirmed galaxies that are detected in radio and
mid-infrared (MIR) in the redshift range of $0.55 \leq z \leq 1.30$ in the
Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey.
We constrain the Active Galactic Nuclei (AGN) contribution in the total IR
luminosity (f$_{\text{AGN}}$), and estimate the AGN luminosity
(L$_{\text{AGN}}$) and the star formation rate (SFR) using the CIGALE Spectral
Energy Distribution (SED) fitting routine. Based on the f$_{\text{AGN}}$ and
radio luminosity, radio-IR galaxies are split into: galaxies that host either
high or low f$_{\text{AGN}}$ AGN (high-/low-f$_{\text{AGN}}$), and star forming
galaxies with little to no AGN activity (SFGs). We study the colour, stellar
mass, radio luminosity, L$_{\text{AGN}}$ and SFR properties of the three
radio-IR sub-samples, comparing to a spec-IR sample drawn from
spectroscopically-confirmed galaxies that are also detected in MIR. No
significant difference between radio luminosity of these sub-samples 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$_{\text{AGN}}$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 timescale 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.
