10323(  1) - 04/02/04 11:59  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      10323
                                                       Version: 1
                                                       Check-in Date: 02-Apr-2004
                                                                      11:58:37

1.Proposal Title:
ORIGIN OF THE GLOBULAR CLUSTER FUNDAMENTAL PLANE
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2. Proposal For  3. Cycle  4. Parallel Pointing Tolerance
AR               13        <none>
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5. Investigators
                                                                                     Contact?
    PI: Dr. Dean E. McLaughlin            Space Telescope Science Institute
   CoI: Dr. Roeland P. van der Marel      Space Telescope Science Institute             N

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6. Abstract

HST has provided many revolutionary new insights on the existence, formation and
properties of star clusters in the Universe. One of the most important findings has
been that star formation in almost any environment involves the formation of massive
stellar clusters which look very much like what is expected of halo globular
clusters when they were young. This discovery has rejuvenated ideas about globular
cluster formation and star formation in general. Nonetheless, our understanding of
the globular cluster formation process remains woefully incomplete. Although the
integrated properties of globular clusters in external galaxies have long been
studied from the ground, only with Hubble has it become possible to resolve the
interiors of individual clusters in the halo of M31 and more distant galaxies. This
has shown that globular clusters always have the same typical half-light radius of
about 3 pc. This generalizes earlier findings for Milky Way clusters to a wide range
of galactic environments and metallicities. Even more, with Hubble it is becoming
increasingly clear that the same is true for young massive clusters. Phrased
differently, the properties of clusters of all types define a remarkably uniform
fundamental plane. While the ubiquity of this plane becomes clearer with every new
Hubble observation, it remains a mystery what processes during cluster formation
regulate its existence. It is also not understood why clusters (size independent of
mass) and galaxies (size increases with mass) follow such different scaling
relations. We will target these questions with a theoretical study of cluster
formation. Using a semi-analytical approach we will study which processes and
parameters are the driving force behind the observed relations. Theoretical work is
badly needed to provide a coherent framework for the interpretation of the many
important cluster results that Hubble has provided. Our study is therefore ideally
suited for the Hubble Theory Program.
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                                                10323(  1) - 04/02/04 11:59  - [  2]

            Summary Form for Proposal  10323

  Item                         Used in this proposal
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  Proposal Category            AR
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