Is there evidence for a spatially homogeneous population of field galaxies
Abstract
A sample of 1095 single (S) and associated (A) galaxies with apparent brightness not less than 14.0 magnitudes is analyzed empirically to determine whether the S galaxies have the statistical properties expected of a field population. Two-point functions describing the clustering of the S galaxies and their correlation with the A galaxies are examined, and the frequency distributions of nearest neighbors are considered for both the S and A galaxies. Cross correlations of the S and A components with fainter galaxies listed in the Zwicky catalog are investigated, the number-magnitude relations for S and A galaxies are discussed, and it is found that both components share the same inhomogeneous clustered distribution around the Galaxy. Model catalogs based on hierarchical clustering are constructed which show that the S component can be accounted for without invoking any field population at all. It is concluded that if there is a galaxy population that might usefully be called a uniform field, it amounts to substantially less than 18% in a sample selected by apparent magnitude. In this case, so-called field galaxies might be members of diffuse outer components of groups and clusters of galaxies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1977
- DOI:
- 10.1086/154898
- Bibcode:
- 1977ApJ...211....1S
- Keywords:
-
- Astronomical Catalogs;
- Cosmology;
- Galactic Clusters;
- Population Theory;
- Cross Correlation;
- Frequency Distribution;
- Galactic Radiation;
- Luminous Intensity;
- Spatial Distribution;
- Astrophysics