7971(  1) - 04/16/98 14:01  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7971
                                                       Version: 1
                                                       Check-in Date: 16-Apr-1998
                                                                      14:00:49

1.Proposal Title:
Fluctuations in the Extragalactic Background Light
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2. Proposal For  3. Cycle
AR               7
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4. Investigators
                                                                                     Contact?
    PI: James E. Gunn                     Princeton University
   CoI: Michael S. Vogeley                Princeton University                          N

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5. Abstract

We propose to apply statistical analyses to deep WFPC2 images to gain important new
constraints on the physical nature and clustering of the Extragalactic Background
Light (EBL). Measurement of optical EBL flucutations is crucial, because
uncertainties in direct observation of the mean optical EBL would admit a large
population of previously undetected extragalactic sources. If a substantial fraction
of the EBL resides in sources that now lie below the detection limits of deep
optical imaging, this population might be inferred from its statistical signature in
the object-masked ``sky.'' Observed upper limits on small-scale EBL fluctuations in
the Hubble Deep Field already rule out many proposed sources of the EBL, thus
demonstrating the power of this approach. We seek to improve these fluctuation
limits, by reducing systematic uncertainties to the level were a detection is
likely. This novel use of archival HST images extends the scientific impact of these
data beyond conventional analysis of detected objects.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
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                                                7971(  1) - 04/16/98 14:01  - [  2]

            Summary Form for Proposal  7971

  Item                         Used in this proposal
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  Proposal Category            AR
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