7536(  1) - 12/14/96 00:45  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7536
                                                       Version: 1
                                                       Check-in Date: 13-Dec-1996
                                                                      18:18:46

1.Proposal Title:
Quantitative Morphology of Cluster
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2. Scientific Category   3. Proposal For  4. Cycle
GALAXIES                    AR               7
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5. Investigators
                                                                                     Contact?
    PI: Dr. Kavan Ratnatunga              Carnegie Mellon University

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6. Abstract

Clusters of galaxies appear to be special environments whose galaxy content changes
considerably with redshift. Strong evolution of field galaxies has also been
detected. We propose to do an objective comparison of the two populations by
generating an uniformly processed HST WFPC2 catalog of galaxies in a wide range of
redshifts and within radically different environments. A coherent sample could pave
the way to a physical framework incorporating all aspects of galaxy formation and
evolution, and benefit the astronomical community. Our primary goal is a systematic
study of the morphology of cluster galaxies at various redshifts, to complement the
existing samples of field galaxies from MDS and other WFPC2 observations. The galaxy
cluster observations from the HST archive will be analyzed with the same semi-
automated pipeline used for the MDS fields. We will focus on the wide band filters
most used (F814W, F702W, F606W, F555W, F450W). We will use maximum likelihood
software to fit simple underlying photometric models (Bulge, Disk, Disk+Bulge) for
the galaxies and obtain sizes and colors. Additional quantitative morphological
parameters will be extracted from the structure overlying the smooth model, to be
analyzed in an objective manner, allowing the data to uncover trends with no
presumption of any evolutionary model from the outset. A similar study of HST field
galaxies has already yielded a mapping of the evolution of galaxies with apparent
magnitude and color.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
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  Email:                                                              ,
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                                                7536(  1) - 12/14/96 00:45  - [  1]

            Summary Form for Proposal  7536

  Item                         Used in this proposal
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  Proposal Category            AR
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  Scientific Category          GALAXIES
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