Stability Limits for 'Isothermal' Cores in Globular Cluster Models: Two-Component Systems.

摘要

Stable equilibria of energy models for stellar systems with two masses m sub and m sub > m sub have been calculated. The models used are those that give the best fit to quasi-isothermal cores of one-mass stellar systems in Monte Carlo calculations. A relation is found between stable quasi-isothermal cores and a critical value around 0.16. Stable quasi-isothermal cores exist for S or = 4, they rapidly disappear as S becomes greater than 0.16. It is also found that, in critically stable configurations with S < or= 0.16, massive stars reduce the total binding energy but augment both the escape energy from the core and the degree of equipartition of energy at the center. To the extent that energy-truncated models are mainly good representations of the core, it is concluded that a small number of massive stars (m2/m1 < or = 10) has a slight stabilizing effect.