The properties of radio galaxies and the effect of environment in large-scale structures at z ~ 1
Journal
Monthly Notices of the Royal Astronomical Society
Journal Volume
472
Journal Issue
1
Pages
998-1022
Date Issued
2017
Author(s)
Shen L
Miller N.A
Lemaux B.C
Tomczak A.R
Lubin L.M
Rumbaugh N
Fassnacht C.D
Becker R.H
Gal R.R
Squires G.
Abstract
In this study, we investigate 89 radio galaxies that are spectroscopically confirmed to be members of five large-scale structures (LSSs) in the redshift range of 0.65 ≤ z ≤ 0.96. Based on a two-stage classification scheme, the radio galaxies are classified into three sub-classes: active galactic nucleus (AGN),Hybrid, and star-forming galaxy (SFG).We study the properties of the three radio sub-classes and their global and local environmental preferences. We find AGN hosts are the most massive population and exhibit quiescence in their star formation activity. The SFG population has a comparable stellar mass to those hosting a radio AGN but are unequivocally powered by star formation. Hybrids, though selected as an intermediate population in our classification scheme, were found in almost all analyses to be a unique type of radio galaxies rather than a mixture of AGN and SFGs. They are dominated by a high-excitation radio galaxy population. We discuss environmental effects and scenarios for each sub-class. AGN tend to be preferentially located in locally dense environments and in the cores of clusters/groups, with these preferences persisting when comparing to galaxies of similar colour and stellarmass, suggesting that their activity may be ignited in the cluster/group virialized core regions. Conversely, SFGs exhibit a strong preference for intermediate-density global environments, suggesting that dusty starbursting activity in LSSs is largely driven by galaxy-galaxy interactions and merging. © 2017 The Authors.
Subjects
Galaxies: active; Galaxies: clusters: general; Galaxies: evolution; Galaxies: groups: general; Galaxies: star formation; Radio continuum: galaxies
Other Subjects
Stars; Addendum; Errata; Galaxies active; Galaxies: clusters: General; Galaxies: groups: generals; Galaxies: star formation; Galaxy evolution; Radio continuum: galaxies; Galaxies
Type
journal article