Clustering of galaxies around radio quasars at 0.5 < z < 0.8

Abstract

We have observed the galaxy environments around a sample of 21 radio-loud, steep-spectrum quasars at 0.5<z<0.82, spanning several orders of magnitude in radio luminosity. The observations also include background control fields used to obtain the excess number of galaxies in each quasar field. The galaxy excess was quantified using the spatial galaxy-quasar correlation amplitude, B_gq, and an Abell-type measurement, N_0.5 (Hill & Lilly 1991). A few quasars are found in relatively rich clusters, but on average, they seem to prefer galaxy groups or clusters of approximately Abell class 0. We have combined our sample with literature samples extending down to z=0.2 and covering the same range in radio luminosity. By using Spearman statistic to disentangle redshift and luminosity dependences, we detect a weak, but significant, positive correlation between the richness of the quasar environment and the quasar's radio luminosity. However, we do not find any epoch dependence in B_gq, as has previously been reported for radio quasars and galaxies. We discuss the radio luminosity-cluster richness link and possible explanations for the weak correlation that is seen.

18 pages, 9 figures, submitted to MNRAS

References in corpus (3)

• The emission line - radio correlation for radio sources using the 7C Redshift Survey
• An X-ray Selected Galaxy Cluster at z=1.26
• A complete sample of radio sources in the North Ecliptic Cap, selected at 38 MHz -- III. further imaging observations and the photometric properties of the sample

Cited by in corpus (52)

• Compact steep-spectrum and peaked-spectrum radio sources
• The Fall of the Quasar Population
• A Census of Intrinsic Narrow Absorption Lines in the Spectra of Quasars at z=2-4
• A sample of radio galaxies spanning three decades in radio luminosity - I. The host-galaxy properties and black-hole masses
• The cluster environments of powerful radio-loud and radio-quiet AGN
• Clustering of Radio Galaxies and Quasars
• The cluster environments of the z~1 3CR radio galaxies
• The link between accretion mode and environment in radio-loud active galaxies
• The environments of luminous radio galaxies and type-2 quasars
• Red galaxy overdensities and the varied cluster environments of powerful radio sources with z~1.6
• A Uniform Analysis of the Ly-alpha Forest at z=0 - 5: V. The extragalactic ionizing background at low redshift
• High redshift FRII radio sources: large-scale X-ray environment
• Associated absorption in radio quasars. I. C IV absorption and the growth of radio sources
• Radio Galaxy Zoo: A Search for Hybrid Morphology Radio Galaxies
• Incorporating Photometric Redshift Probability Density Information into Real-Space Clustering Measurements
• CENSORS: A Combined EIS-NVSS Survey Of Radio Sources. I. Sample definition, radio data and optical identifications
• Radio-loud AGN: is there a link between luminosity and cluster environment?
• Radio-quiet quasar environments at 0.5 < z < 0.8
• Extended X-ray emission around four 3C quasars at 0.55<z<0.75 observed with Chandra
• Overdensities of Extremely Red Objects in the Fields of High-Redshift Radio-Loud Quasars
• Low-power radio galaxy environments in the Subaru/XMM-Newton Deep Field at z~0.5
• Cluster of galaxies around seven radio-loud QSOs at 1<z<1.6: K-band images
• Low redshift quasars in the SDSS Stripe 82. The local environments
• Searching High Redshift Large-Scale Structures: Photometry of Four Fields Around Quasar Pairs at z~1
• X-rays from the Type II quasar in the hyperluminous infrared galaxy IRAS F15307+3252
• Tracing high redshift cosmic web with quasar systems
• XMM-Newton Surveys of the Canada-France Redshift Survey Fields - III: The Environments of X-ray Selected AGN at 0.4<z<0.6
• Heating of the Hot Intergalactic Medium by Powerful Radio Galaxies and Associated High Energy Gamma-Ray Emission
• Environments of Nearby Quasars in Sloan Digital Sky Survey
• The cluster environments of radio-loud quasars at 0.6 < z < 1.1
• The radio galaxy 3C 356 and clues to the trigger mechanisms for powerful radio sources
• RXJ0142.0+2131: I. The galaxy content of an X-ray-luminous galaxy cluster at z=0.28
• A Study of 3CR Radio Galaxies from z = 0.15 to 0.65. I. Evidence for an Evolutionary Relationship Between Quasars and Radio Galaxies
• The Massive and Distant Clusters of WISE Survey VII: The Environments and Properties of Radio Galaxies in Clusters at z~1
• The environments of hyperluminous infrared galaxies at 0.44<z<1.55
• The host galaxies of radio-quiet quasars at 0.5<z<1.0
• The Clustering of AGN and Galaxies at Intermediate Redshift
• The Environment of Local Ultraluminous Infrared Galaxies
• Early Science Result from the Japanese Virtual Observatory: AGN and Galaxy Clustering at z = 0.3 to 3.0
• Tunable-filter imaging of quasar fields at z ~ 1. II. The star-forming galaxy environments of radio-loud quasars
• Downsizing of Star Formation Measured from the Clustered Infrared Background Correlated with Quasars
• The depolarisation properties of powerful extragalactic radio sources as a function of cosmic epoch
• The environment of active objects in the nearby universe
• Detection of 20-30 Mpc-scale Galaxy Structures Embedded in 100 Mpc-scale Structures of Quasars and MgII Absorbers at z~0.8 and z~1.2
• Interplanetary Scintillation studies with the Murchison Wide-field Array IV: The hosts of sub-arcsecond compact sources at low radio frequencies
• HST imaging survey of sub-mJy star-forming galaxies I: morphologies at z ~ 0.2
• Fundamental properties of Fanaroff-Riley II radio galaxies investigated via Monte Carlo simulations
• Superdisks and the structural asymmetry of radio galaxies
• PKS 0537-441: extended [O II] emission and a binary QSO?
• Clustering environment of BL Lac object RGB 1745+398
• Spatial clustering of USS sources and galaxies
• The Radio Galaxy Environment Reference Survey (RAGERS): a submillimetre study of the environments of massive radio-quiet galaxies at $z=1-3$