Stochastic dynamics toward the steady state of self-gravitating systems

Tashiro, Toru*; Tatekawa, Takayuki

The behavior of a self-gravitating system (SGS) is described using the equilibrium statistical mechanics. Although the behavior of the system is analytically solved for the spherically symmetric system, it is known that mass density in the central region and/or total mass of the system sometimes diverges. King model which is derived by modification of the statistical mechanics can explain the distribution without these difficulties. We construct a theory which can explain the dynamics toward the special steady state described by the King model. SGSs require quite long time for relaxation. Furthermore, we must compute interaction of all particle pairs. By these reasons, we require huge computation power for numerical simulation of the evolution of SGS. So we have applied special-purpose processor for computation of the interaction. From the numerical simulations of SGS, we have confirmed that our theory is appropriate for description of realistic density distribution.