Energy equipartition in multiple-population globular clusters

TL;DR

This study uses Monte Carlo simulations to investigate how initial spatial differences between multiple stellar populations in globular clusters influence their evolution towards energy equipartition, revealing that initial concentration affects the rate and extent of this process.

Contribution

It demonstrates that initial spatial distributions significantly impact the energy equipartition evolution of multiple populations in globular clusters, especially for second-generation stars.

Findings

2G stars evolve faster towards energy equipartition due to initial central concentration.

Energy equipartition evolution varies with velocity component, faster tangentially.

Differences in energy equipartition are more pronounced at intermediate radii and depend on cluster age.

Abstract

We present the results of Monte Carlo simulations aimed at exploring the evolution towards energy equipartition of first- (1G) and second-generation (2G) stars in multiple-population globular clusters and how this evolution is affected by the initial differences between the spatial distributions of the two populations. Our results show that these initial differences have fundamental implications for the evolution towards energy equipartition of the two populations. We find that 2G stars, which are assumed to be initially more centrally concentrated than 1G stars, are generally characterized by a more rapid evolution towards energy equipartition. The evolution towards energy equipartition depends on the velocity dispersion component and is more rapid for the tangential velocity dispersion. The extent of the present-day differences between the degree of energy equipartition of 2G and 1G stars depends on the cluster's dynamical age and may be more significant in the tangential velocity dispersion and at intermediate distances from the cluster's center around the half-mass radius.