Formation and Early Evolution of Stellar Clusters

Abstract

We describe a novel numerical method for the studying the formation and evolution of stellar clusters, Torch. This method combines the magnetohydrodynamics code Flash with the Astrophysical Multipurpose Software Environment, AMUSE. Once embedded into AMUSE, we combine Flash with the stellar evolution code SeBa, the N-body dynamics code ph4 and the multiple star system evolution module multiples to create a unique method for tracing the detailed evolution of stellar clusters through time. We then add units for radiation, stellar winds and supernovae, as well as a new star by star formation prescription to Flash that allows for star formation and stellar feedback to create and destroy star clusters and the interstellar gas they form from. The result is the most detailed star cluster formation code to date. We then demonstrate the use of these methods for studying binary star formation and the effects of stellar feedback. We find that massive dynamical binaries created in our simulations are consistent with observations. Further, we observe that wide dynamical binaries tighten due to gas dynamical friction, losing cluster energy to the natal gas, after which they are disrupted by stellar encounters. This supports theoretical predictions that embedded clusters may contract due to the interactions of gas and stars. We also find that while stellar feedback is effective at expelling gas from natal clusters, the clusters themselves remain bound even as they expand due to the loss of the binding potential of the gas. Finally, stellar clusters formed in our simulations mass segregate before the expulsion of their natal gas clouds, as expected from observations of young clusters in the Milky Way.Ph.D., Physics -- Drexel University, 201