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Dynamical Masses of Young Star Clusters: Constraints on the Stellar IMF and Star-Formation Efficiency

Published online by Cambridge University Press:  01 September 2007

N. Bastian*
Affiliation:
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK email: bastian@star.ucl.ac.uk
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Abstract

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Through the use of detailed light profiles and dynamical measurements of young clusters we investigate claims that the stellar initial mass function within clusters varies greatly. We find a strong age dependence in the clusters which have been claimed to have non-standard stellar IMFs, and suggest that the lack of equilibrium of these clusters is responsible for their ‘strange’ light-to-mass ratios and not IMF variations. The most likely culprit is the rapid removal of residual gas left over from the star-formation process which leaves the clusters severely out of dynamical equilibrium. By comparing the observations to N-body simulations we quantify to what degree a cluster is out of equilibrium and consequently its survival chances. We find that >60% of young clusters will be disrupted, due gas removal, within the first 20–50 Myr of their lives.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2008

References

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