A Monte Carlo study of early gas expulsion and evolution of star clusters: new simulations with the MOCCA code in the AMUSE framework

TL;DR

This paper presents a new Monte Carlo simulation approach within the AMUSE framework to study early gas expulsion effects on globular cluster evolution, enabling rapid exploration of larger systems than traditional N-body methods.

Contribution

It introduces a simplified Monte Carlo method for early cluster evolution, validated against N-body results, and explores a wide parameter space for cluster survival.

Findings

Identifies initial conditions leading to cluster dissolution.

Demonstrates the efficiency of the Monte Carlo approach for large N systems.

Provides insights into early cluster evolutionary phases.

Abstract

We introduce a new prescription for the evolution of globular clusters (GCs) during the initial embedded gas phase into a Monte Carlo method. With a simplified version of the Monte Carlo MOCCA code embedded in the AMUSE framework, we study the survival of GCs after the removal of primordial gas. We first test our code and show that our results for the evolution of mass and Lagrangian radii are in good agreement with those obtained with N-body simulations. The Monte Carlo code enables a more rapid exploration of the evolution of systems with a larger number of stars than N-body simulations. We have carried out a new survey of simulations to explore the evolution of globular clusters with up to $N = 500000$ stars for a range of different star formation efficiencies and half-mass radii. Our study shows the range of initial conditions leading to the clusters' dissolution and those for which the clusters can survive this early evolutionary phase.