8368(  2) - 12/18/98 16:49  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8368
                                                       Version: 2
                                                       Check-in Date: 18-Dec-1998
                                                                      16:48:15

1.Proposal Title:
Constraints on the Evolution of Dwarf Elliptical Galaxies from Deep HST images
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2. Proposal For  3. Cycle
AR               8
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4. Investigators
                                                                                     Contact?
    PI: Henry C. Ferguson                 Space Telescope Science Institute
   CoI: Ms. Jennifer Lotz                 The Johns Hopkins University                  N

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5. Abstract

The aim of this program is to test models for the late (z <~ 1) formation of dwarf
elliptical galaxies. Such late formation arises as a fairly natural consequence of
proposed solutions to the ``overcooling'' problem in theories of hierarchical
structure formation. Correlations of dwarf galaxy numbers and ages with the density
of the environment are also predicted. The data exist now to test such hypotheses.
We will construct models of dE galaxy evolution -- constrained to be consistent with
color and luminosity distributions in local samples -- and compare them directly to
deep HST images of clusters and blank fields. A range of luminosity function shapes
and normalizations will be tested to identify those that are consistent or
inconsistent with the number counts of dE-like galaxies in blank fields such as the
HDF, and in the fields of high-redshift clusters. The models will take into account
spectrophotometric evolution, density evolution, the possible morphological
transformation of irregular galaxies to dE's, and selection effects.
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  Data Distribution

  Paper Products:  NO
  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
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                                                8368(  2) - 12/18/98 16:49  - [  2]

            Summary Form for Proposal  8368

  Item                         Used in this proposal
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  Proposal Category            AR
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