2002/05/23 by Georgina Coldwell, Georgina V. Coldwell, Héctor J. Martínez +3 · 1 citation
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Dark galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy group #Luminous infrared galaxy #Physics #Quasar #Radio galaxy #Redshift #Stellar, planetary, and galactic studies #Universe #X-shaped radio galaxy #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2002.05713.x
published as Mon.Not.Roy.Astron.Soc. 336 (2002) 207 · 5 pages, 3 figures, to appear in MNRAS
arxiv created 2002/05/23 · openalex publication_date 2002/10/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the galaxy environment of active galaxies, radio-loud and radio-quiet quasars in the redshift range 0.1 ≤z≤ 0.25. We use galaxies from the APM survey in order to explore the local galaxy overdensity and the bJ−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 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 overdensities of radio-loud and radio-quiet quasars are comparable. The analysis of the distribution of bJ−R galaxy colour indices suggests that the environment of quasars is not strongly dominated by a population of red galaxies, characteristic of rich Abell clusters, an effect that is more clearly appreciated for our sample of radio-loud quasars.