Two Body Capture in Large N Body Systems

Abstract

I have considered the rates of formation of binaries in the following processes: two-body tidal encounters, three-body encounters, self-hardening of soft binaries formed in three-body encounters and two-body encounters connected with gravitational wave radiation. I have considered also the cooling and the heating connected with formation of binaries and the subsequent interactions of binaries with single stars. I have found that the rate of formation of heating binaries in two-body tidal encounters differs from that calculated by Ozernoy and Dokuchaev (1982). These differences are connected first of all with the precise calculation of the dissipated energy of two stars passing near-by each other, maximum and minimum binary binding energy and also with the use of the incomplete gamma function instead of gamma function. The processes presently predominat in the globular cluster conditions are the formation of hard binaries in two-body tidal encounters between evolved and unevolved stars and cooling connected with collisions between white dwarfs and main sequence stars and between white dwarfs. In the systems of density greater than 109pc−3 the binaries formed in three-body encounters (and to a smaller extent self-hardening of soft binaries formed in three-body encounters) predominate the globular cluster evolution. In the globular cluster heating by hard binaries exceedes cooling associated with the tidal interactions and collisions of stars.