The growth of density correlation in an oscillating spherical stellar system. The case of small correlation.
Abstract
The violent relaxation processes experienced by stellar systems such as elliptical galaxies are believed to result from violent fluctuations of the gravitational potential caused in part by the growth of largeamplitude density correlations during the contraction stage. This paper investigates how density correlations grow in oscillating stellar systems, using a sort of generalization of the virial method employed in hydrodynamics to study an isolated spherical system of point particles oscillating with nearly uniform density. The dynamic behavior of this system is described by the BBGKY hierarchy equations, and collective interactions among the particles are neglected. The virial theorem is derived from the first equation of the BBGKY hierarchy, the theorem is extended to analyze the dynamic evolution of the density correlation, and the dynamic behavior of certain integrated quantities is examined for a spherical stellar system having nearly homogeneous density and oscillating almost homologously. The results indicate that the density correlation grows rapidly in a cyclic manner in an oscillating stellar system.
 Publication:

Publications of the Astronomical Society of Japan
 Pub Date:
 1976
 Bibcode:
 1976PASJ...28..617K
 Keywords:

 Elliptical Galaxies;
 Galactic Evolution;
 Galactic Structure;
 Space Density;
 Stellar Systems;
 Virial Theorem;
 Astrodynamics;
 Data Correlation;
 Hierarchies;
 Integral Equations;
 Mathematical Models;
 Astrophysics