7520(  1) - 12/14/96 00:19  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7520
                                                       Version: 1
                                                       Check-in Date: 13-Dec-1996
                                                                      18:13:37

1.Proposal Title:
Galaxy Masses from Cluster Arcs
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2. Scientific Category   3. Proposal For  4. Cycle
CLUSTERS OF GALAXIES        AR               7
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5. Investigators
                                                                                     Contact?
    PI: Roger Blandford                   Caltech
   CoI: Tomislav Kundic                   Caltech                                       N
   CoI: Mark Metzger                      Caltech                                       N

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6. Abstract

It is proposed to use existing, archival observations of giant arcs in distant rich
clusters of galaxies to estimate or limit the masses of field galaxies. The
technique that is proposed is to measure perturbations in the giant arc shapes that
are caused by intervening galaxies. The amplitude of these perturbations, whose
shape can be modeled when one knows the locations and redshifts of the principle
perturbers, is a measure of their mean, interior surface density and, for larger
impact parameters, the extent of the dark matter halos. It is intended to scrutinize
the entire archive of HST images of distant rich clusters and identify all the
instances of galaxies in close proximity to well-resolved arcs. The arc images will
be modeled using smooth cluster models and these will be augmented with parametrized
galactic perturbations. In this way, it is intended to obtain good limits on the
masses and sizes of distant field galaxies.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:                                                              ,
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                                                7520(  1) - 12/14/96 00:19  - [  1]

            Summary Form for Proposal  7520

  Item                         Used in this proposal
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  Proposal Category            AR
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  Scientific Category          CLUSTERS OF GALAXIES
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