The structure of young star clusters in the Large Magellanic Cloud

The authors present surface brightness profiles, based on star counts and aperture photometry, for 10 rich young star clusters in the Large Magellanic Cloud. To investigate the dynamical evolution of the clusters, they derive mass-to-light ratios from stellar population models. They consider various ways in which the clusters might have formed, and suggest several explanations for the observed profiles. Expansion of a newly formed cluster either through mass loss or during violent relaxation could lead to the formation of a halo of unbound stars. To examine this possibility, a calculation of the tidal field of the LMC is included. At least some and perhaps all the clusters in the sample extend beyond their eventual tidal radii, with up to 50% of the total masses in unbound halos.