Gravitational Clustering of Galaxies: Comparison of Thermodynamic Theory and NBody Simulations. II. The Effects of Different Mass Components
Abstract
The thermodynamic theory of gravitational galaxy clustering gives a good description of the galaxy distribution for both Nbody simulations and observations. This theory and our previous Nbody simulations, however, assume that all the galaxies have the same mass m. We now investigate the effects of mass spectra using new Nbody simulations with two mass components (m_1_ and m_2_) and find that thermodynamic theory is applicable to twocomponent systems as long as the mass ratio of two components is in the approximate range of m_1_:m_2_ = 1:111:10. Our analyses show that the massive galaxies provide nuclei for clusters and speed up clustering in early stages, but these individual effects disappear and collective interactions dominate in late stages. The number of massive galaxies which are contained in clusters tends to increase as the mass ratio becomes larger. We describe the quantitative role that massive galaxies play in seeding clusters. The singlecomponent thermodynamic theory does not describe the Nbody simulations for extreme mass ranges of m_2_/m_1_ >~ 15.
 Publication:

The Astrophysical Journal
 Pub Date:
 June 1990
 DOI:
 10.1086/168842
 Bibcode:
 1990ApJ...356..315I
 Keywords:

 Computational Astrophysics;
 Galactic Clusters;
 Gravitational Effects;
 Many Body Problem;
 Thermodynamics;
 Distribution Functions;
 Galactic Evolution;
 Galactic Mass;
 Identifying;
 Mass Spectra;
 Spatial Distribution;
 Astrophysics;
 COSMOLOGY;
 GALAXIES: CLUSTERING;
 GRAVITATION;
 NUMERICAL METHODS