Post-collapse evolution of globular clusters with finite number of stars in the core

To study the post-collapse evolution of clusters, where fluctuations are significant due to the number of stars in the cluster core being of the order of 100, N-body experiments with N = 1000 and 3000 were conducted. The effects of the finite size of stars are not considered, and a point-mass approximation is assumed. The analysis indicates that the core oscillates with an amplitude of the order of 10 in density (an amplitude much lower that that found in the fluid model of star clusters) and that these oscillations are directly related to binary activity. It is suggested that this phenomenon also occurs in systems with N equal to one million, and that core oscillations continue for a long time, with the period of oscillations becoming increasingly longer.