Nature or Nurture: Sources of Stellar Clusters’ Mass Segregation in the STARFORGE Simulations

In observations, massive stars are often found in the centers of stellar clusters. It is currently unknown if this mass segregation is caused by the inward migration of massive stars due to N-body processes during the evolution of the cluster, or if these massive stars are simply born in this formation. In analyzing simulations of the evolution of Giant Molecular Clouds from the STARFORGE simulation suite, we find that massive stars are born at different star formation sites within initially mass-segregated, smaller sub-clusters. As the cloud evolves these subclusters grow and merge to form larger structures that ultimately end up mass-segregated due to dynamical processes.