# The Emergence of Multiple Populations in Radiation Hydrodynamics Simulations of Cluster Formation

## TL;DR

This paper uses radiation hydrodynamics simulations to explore how multiple stellar populations with different chemical abundances naturally form during the process of star cluster formation within molecular clouds.

## Contribution

It introduces a new simulation-based framework to understand the origin of multiple populations in globular clusters, considering dynamic chemical enrichment and cluster assembly processes.

## Key findings

- Multiple populations can form through different enrichment mechanisms.
- Cluster formation histories are influenced by stochastic merging and accretion.
- Diverse abundance patterns naturally arise in simulated clusters.

## Abstract

We present a new approach to understanding star-to-star helium abundance variations within globular clusters. We begin with detailed radiation hydrodynamics simulations of cluster formation within giant molecular clouds, and investigate the conditions under which multiple populations could be created. Chemical enrichment occurs dynamically as the cluster is assembled. We test two extreme mechanisms for injection of enriched gas within the clusters, and find that realistic multiple populations can be formed in both mechanisms. The stochastic cluster formation histories are dictated by the inherent randomness of the timing and location of the formation of small clusters, which rapidly merge to build up the larger cluster, in combination with continual accretion of gas from the cloud. These cluster formation histories naturally produce a diversity of abundance patterns across the massive cluster population. We conclude that multiple populations are a natural outcome of the typical mode of star cluster formation.