7523(  1) - 12/14/96 00:22  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7523
                                                       Version: 1
                                                       Check-in Date: 13-Dec-1996
                                                                      18:14:28

1.Proposal Title:
Spheroidal Galaxy Evolution
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2. Scientific Category   3. Proposal For  4. Cycle
COSMOLOGY                   AR               7
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5. Investigators
                                                                                     Contact?
    PI: Tom Broadhurst                    University of California, Berkeley
   CoI: Francine Marleau                  University of California, Berkeley            N
   CoI: Stephane Charlot                  Institut d'Astrophysique du CNRS              N

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6. Abstract

We propose to use archival WFPC2 images for exploring the evolution of spheroidal
galaxies. The deep field V and I pointings deserve special attention, being faint
enough and of sufficient angular resolution for detecting young early-type galaxies
when hot stars should populate the upper main- sequence. Our analysis of the Hubble
Deep Field (HDF) field demonstrates the existence of a tight track in the color-
magnitude plane for de Vaucouleurs profile galaxies, extending from moderate
redshift red colors to the bright blue early stages, consistent with a passively
evolving population. With more fields from the archive we can constrain the density
evolution all along the sequence and define better their spread in age.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:                                                              ,
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                                                7523(  1) - 12/14/96 00:22  - [  1]

            Summary Form for Proposal  7523

  Item                         Used in this proposal
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  Proposal Category            AR
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  Scientific Category          COSMOLOGY
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