The environment of active objects in the nearby universe

Abstract

We study the galaxy environment of active galaxies, radio-loud and radio-quiet quasars in the redshift range $0.1\le z\le 0.25$. We use APM galaxies in order to explore the local galaxy overdensity and the $b_J-R$ colour distribution of neighbouring galaxies of these target samples. For comparison, we perform similar analysis on samples of Abell clusters with X-ray emission, and samples of Abell clusters with richness R=1 and R=0. The projected cross-correlations show that the samples of quasars and active galaxies reside in regions of galaxy density enhancements lower than those typical of R=0 clusters. We also find that in the nearby universe the local galaxy overdensity of radio-loud and radio-quiet quasars are comparable. The analysis of the distribution of $b_J-R$ galaxy colour indexes suggests that the environment of quasars is not strongly dominated by a population of red galaxies, characteristic of rich Abell cluster, an effect that is more clearly appreciated for our sample of radio-loud quasars.

5 pages, 3 figures, to appear in MNRAS

References in corpus (5)

• The cluster environments of powerful radio-loud and radio-quiet AGN
• The cluster environments of the z~1 3CR radio galaxies
• Clustering of galaxies around radio quasars at 0.5 < z < 0.8
• Radio-quiet quasar environments at 0.5 < z < 0.8
• The environments of intermediate-redshift QSOs: 0.3 < z < 0.7

Cited by in corpus (10)

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• Properties of galaxies in SDSS Quasar environments at z < 0.2
• AGN Environments in the Sloan Digital Sky Survey I: Dependence on Type, Redshift, and Luminosity
• Searching High Redshift Large-Scale Structures: Photometry of Four Fields Around Quasar Pairs at z~1
• The Evolution and Environments of X-ray Emitting Active Galactic Nuclei in High-Redshift Large-Scale Structures
• Local and large-scale effects on the astrophysics of void-galaxies
• Triplets of Quasars at high redshift I: Photometric data
• The Two-Point Correlation of 2QZ Quasars and 2SLAQ LRGs: From a Quasar Fueling Perspective
• Wide Field Multiband Imaging of Low Redshift Quasar Environments