9521(  1) - 12/06/01 12:33  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      9521
                                                       Version: 1
                                                       Check-in Date: 06-Dec-2001
                                                                      11:44:15

1.Proposal Title:
Star Formation Histories of Local Group Galaxies
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2. Proposal For  3. Cycle
AR               11
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4. Investigators
                                                                                     Contact?
    PI: Andrew Dolphin                    National Optical Astronomy Observatories
   CoI: Dr. Jon Holtzman                  New Mexico State University                   N
   CoI: Dr. Cristina Afonso               New Mexico State University                   N
   CoI: Dr. Evan Skillman                 University of Minnesota                       N
   CoI: Dr. Robbie Dohm-Palmer            University of Michigan                        N

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5. Abstract

The HST has provided a large quantity of deep photometry of the stellar content of
Local Group galaxies, which can be used to understand their star formation histories
(SFHs) to unprecedented accuracy. Because of the difficulties of measuring a SFH
from a CMD, however, a significant amount of this potential knowledge remains yet
untapped. Many groups have developed tools to attempt this task; however differences
of philosophy between the groups lead to conflicting results -- even when applied to
the sam e data. We propose a comprehensive effort for the development, testing, and
releasing of analysis tools that will remedy this limitation. The proposed project
will allow us to scrutinize each of the algorithms that have been suggested in
controlled test s, determine which are best-suited for the task, and produce a
technique (or set of techniques) with which we can confidently measure the SFHs of
Local Group galaxies previously observed by HST. These techniques will then be
applied to our extensive WFPC 2 photometry database, and SFHs will be measured for
the majority of Local Group galaxies. We believe that the accurate and unambiguous
interpretation of CMDs -- the subject of dozens of WFPC2 programs -- can only be
done textitafter the required tech niques and algorithms have been comprehensively
examined, and that this project will allow these data to be used to their fullest
potential.
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                                                9521(  1) - 12/06/01 12:33  - [  2]

            Summary Form for Proposal  9521

  Item                         Used in this proposal
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  Proposal Category            AR
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