Assigned ID: 410 ----- Attempting Submission 1 (Fri Feb 26 16:55:04 GMT 2010) ----- The possibility that stellar clusters may disrupt and dissolve at young ages has far-reaching consequences for our understanding of star formation and galaxy evolution, including the number of modes of star formation, the low-end of the stellar initial mass function, and how reliably stellar clusters trace the parent galaxy's population. However, this crucial stage of cluster evolution is still poorly constrained both theoretically and observationally. Unlike young, bright clusters, or globular clusters, dissolving star clusters are usually too scattered and have too low surface brightnesses to be detected in traditional surface photometric studies. Therefore, the physical parameters that determine whether, how, and on which timescale a young stellar cluster will dissolve are not constrained yet. We propose to study the importance of various physical processes on the dissolution of young star clusters using a sample of 25 nearby galaxies. Our new technique utilizes the high spatial resolution and sensitivity of HST/ACS to detect individual stars in galaxies as far as 5 Mpc in multiple colors (~BVI). A clustering algorithm, together with stellar population synthesis models, will allow us to find groups of stars and obtain their ages, stellar masses, sizes, and compactness. Our sample covers a wide range of galaxy properties (morphology, luminosity, structure [bars, etc.], metallicity, activity level), and will enable us to study the impact of various environmental parameters on the dissolution and disruption processes. This will be the first extensive study of a poorly constrained aspect of star cluster evolution, and optimally leverages on the rich HST archival data.

RESOLVED STELLAR POPULATIONS 12 107423 false 0.0 0.0 false false false false false false SUPPORTED