7524(  1) - 12/14/96 00:26  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7524
                                                       Version: 1
                                                       Check-in Date: 13-Dec-1996
                                                                      18:14:45

1.Proposal Title:
The Nature of Faint, Blue, I-K>4
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2. Scientific Category   3. Proposal For  4. Cycle
COSMOLOGY                   AR               7
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5. Investigators
                                                                                     Contact?
    PI: Prof. Marc Davis                  University of California
   CoI: Leonidas Moustakas                University of California                      N
   CoI: Dr. Steve Zepf                    University of California                      N

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6. Abstract

We propose to combine HST archival data in the deep field of the Groth Survey Strip
(dGSS) and in the clusters Cl0024, Cl0939, and Abell370 with deep near-infrared Keck
observations, to identify and study a class of very faint (I~gt 25) galaxies that
have quite peculiar optical-infrared colors (V-I=0-2; I-K>4). The colors of the
``red outlier galaxies,'' or ROGs, are not easy to reproduce, and are due to either
an old underlying population of stars in the galaxy, or to a highly reddened bright
nucleus central region. In either case, they are likely to lie at z~gt 1.2.
Combining the extant F606W and F814W HST data with the corresponding Keck K band
(2.2Mu m) data, we will identify a large number of the ROGs since their surface
density is rather high, several per square arcminute. Studying the numbers and
morphology of ROGs found in the field and in or behind the (z~ 0.4) clusters will
help distinguish between age and dust being responsible for the ROGs colors. This
project will thus help us gain a better understanding of the formation epoch and
history of galaxy evolution.
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  Data Distribution

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  Blocking Factor: 10
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                                                7524(  1) - 12/14/96 00:26  - [  1]

            Summary Form for Proposal  7524

  Item                         Used in this proposal
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  Proposal Category            AR
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  Scientific Category          COSMOLOGY
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