A statistical investigation of radio sources in the directions of Zwicky clusters of galaxies.
Abstract
In order to extend the available information on radio sources in clusters of galaxies, a statistical investigation is made of the positional coincidences between 3CR radio sources and Zwicky clusters of galaxies. Although the analysis of Zwicky's catalog suggests that the catalog is incomplete for less compact clusters at large distances, several general conclusions are possible. The number of coincidences between 0.5 and 2 cluster radii is consistent with the number expected by chance, whereas an excess of about 14 3CR sources was found within 0.5 cluster radii. This statistical excess agrees well with the number of identified 3CR radio galaxies associated with Zwicky clusters (16). Thus, few if any of the other sources in the directions of Zwicky clusters (blank fields, OSOs, etc.) are likely to be physically associated with clusters. A list of 13 cluster and nine field 3CR sources with redshifts of no more than 0.1 was compiled for the purpose of structure comparisons. From an analysis of available radio contour maps and brightness data, it was found that Zwicky clusters tend to have lower radio luminosities, greater spectral indices, and more diffuse structure than field sources.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1977
- DOI:
- 10.1086/155549
- Bibcode:
- 1977ApJ...217...34B
- Keywords:
-
- Astronomical Catalogs;
- Extragalactic Radio Sources;
- Galactic Clusters;
- Statistical Analysis;
- Brightness;
- Completeness;
- Density (Number/Volume);
- Galactic Structure;
- Intergalactic Media;
- Luminosity;
- Quasars;
- Radio Galaxies;
- Astronomy