Comparative study between N-body and Fokker-Planck simulations for rotating star clusters: I. Equal-mass system

TL;DR

This study compares N-body and Fokker-Planck simulations of rotating equal-mass star clusters, showing similar overall evolution but differences in detailed dynamics, and highlights the impact of initial angular momentum on core collapse.

Contribution

It provides a direct comparison between N-body and Fokker-Planck models for rotating star clusters, emphasizing the effects of initial angular momentum on cluster evolution.

Findings

Both models show accelerated core collapse due to initial rotation.

Central density and velocity dispersion evolve similarly in both models.

Angular momentum is gradually lost through star evaporation.

Abstract

We have carried out N-body simulations for rotating star clusters with equal mass and compared the results with Fokker-Planck models. These two different approaches are found to produce fairly similar results, although there are some differences with regard to the detailed aspects. We confirmed the acceleration of the core collapse of a cluster due to an initial non-zero angular momentum and found a similar evolutionary trend in the central density and velocity dispersion in both simulations. The degree of acceleration depends on the initial angular momentum. Angular momentum is being lost from the cluster due to the evaporation of stars with a large angular momentum on a relaxation time scale.