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Title: Early-forming Massive Stars Suppress Star Formation and Hierarchical Cluster Assembly

Feedback from massive stars plays an important role in the formation of star clusters. Whether a very massive star is born early or late in the cluster formation timeline has profound implications for the star cluster formation and assembly processes. We carry out a controlled experiment to characterize the effects of early-forming massive stars on star cluster formation. We use the star formation software suiteTorch, combining self-gravitating magnetohydrodynamics, ray-tracing radiative transfer,N-body dynamics, and stellar feedback, to model four initially identical 104Mgiant molecular clouds with a Gaussian density profile peaking at 521.5 cm−3. Using theTorchsoftware suite through theAMUSEframework, we modify three of the models, to ensure that the first star that forms is very massive (50, 70, and 100M). Early-forming massive stars disrupt the natal gas structure, resulting in fast evacuation of the gas from the star-forming region. The star formation rate is suppressed, reducing the total mass of the stars formed. Our fiducial control model, without an early massive star, has a larger star formation rate and total efficiency by up to a factor of 3, and a higher average star formation efficiency per freefall time by up to a factor of 7. Early-forming massive stars promote the buildup more » of spatially separate and gravitationally unbound subclusters, while the control model forms a single massive cluster.

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The Astrophysical Journal
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Article No. 211
DOI PREFIX: 10.3847
Sponsoring Org:
National Science Foundation
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