On equipartition of kinetic energies in two-component star clusters.

The dynamical evolution of two-component star clusters is studied by solving the isotropized orbit-averaged Fokker-Planck equation. The simulations are started from Plummer's model with the same velocity dispersion between the components. It is found that the global equipartition is never achieved even if the fraction of the more massive stars is very small. The temperature difference in the core is very small if the fraction of the more massive stars is small. The larger the fraction of the more massive stars is, the larger is the termperature difference in the core. The late stage of the evolution is governed by the more massive component. The more massive component collapses independently of the less massive component and the less massive component follows the collapse of the more massive stars, owing to the strong gravitational field of the more massive component.