Relaxation with close encounters in stellar systems.
Abstract
Previous applications of the KolomogorovFeller (KF; 1940) equation to the problem of the relaxation of the velocity distribution in a star cluster are reviewed. Solutions to the KF equation are presented in which earlier shortcomings concerning encounters with a small velocity increment are corrected. Results are reported for calculations of steadystate velocity distributions, theoretical estimates of the number of stars that escape due to sudden energy gains during close encounters, and a theoretical estimate of the fraction of kinetic energy carried away by escaping stars. These results are compared with corresponding solutions to the FokkerPlanck equation.
 Publication:

The Astronomical Journal
 Pub Date:
 March 1979
 DOI:
 10.1086/112432
 Bibcode:
 1979AJ.....84..370R
 Keywords:

 Celestial Mechanics;
 Relaxation (Mechanics);
 Star Clusters;
 Stellar Motions;
 Stellar Systems;
 Velocity Distribution;
 Escape Velocity;
 FokkerPlanck Equation;
 MaxwellBoltzmann Density Function;
 Astrophysics;
 Relaxation:Stellar Systems;
 Star Clusters:Velocity Distribution;
 Stellar Systems:Close Encounters