Structure of superclusters and supercluster formation - III. Quantitative study of the Local Supercluster

Abstract

The structure of the Local Supercluster is investigated using data on the three-dimensional distribution of galaxies. The quantitative methods used include correlation and multiplicity analyses and clustering and percolation methods. The distributions observed are compared with model distributions obtained from simulated Poisson, adiabatic, and simple hierarchical samples. It is found that galaxy systems of different size and density contrast can be separated in the Local Supercluster by cluster analysis. The supercluster can be broken down into cluster and strings of galaxies. It is noted that clusters are density enhancements in strings, and strings are constituent parts of superclusters. Galaxy strings constitute bridges between superclusters and join all superclusters to a single infinite network. Systems of galaxies are thus not isolated objects. Whereas simple hierarchical models as well as the Poisson model have properties that are completely different from the observed distribution, adiabatic models fit the observations much better.