The formation and evolution of small star clusters

Recent observations show that small, young, stellar groupings of similar to 10 to 40 members tend to have a centrally located most massive member, reminiscent of mass segregation seen in large clustered systems. Here, we analyse hydrodynamic simulations which form small clusters and analyse their properties in a manner identical to the observations. We find that the simulated clusters possess similar properties to the observed clusters, including a tendency to exhibit mass segregation. In the simulations, the central location of the most massive member is not due to dynamical evolution, since there is little interaction between the cluster members. Instead, the most massive cluster member appears to form at the centre. We also find that the more massive stars in the cluster form at slightly earlier times.