10683(  1) - 04/05/05 12:36  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      10683
                                                       Version: 1
                                                       Check-in Date: 05-Apr-2005
                                                                      16:36:13

1.Proposal Title:
S0 Evolution from Archival HST Images
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2. Proposal For  3. Cycle  4. Parallel Pointing Tolerance
AR               14        <none>
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5. Investigators
                                                                                     Contact?
    PI: Dr. James Schombert               University of Oregon
   CoI: Dr. Karl D. Rakos                 University of Vienna                          N

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6. Abstract

This is an archival project to study the structural properties of S0 galaxies as a
function of redshift. S0 galaxies divide into those with bulge+disk structure
(classic S0's) and those composed of a pure exponential disk structure
(lenticulars). While studying the structural properties of the blue Butcher-Oemler
population in distant clusters, we discovered that intermediate redshifts clusters
are rich in B+D type S0's, but in nearby clusters the S0 population is dominated by
lenticulars. The hypothesis to be tested is that B+D S0's are stripped of their
disks at intermediate redshifts to become ellipticals, while the blue population
fades into lenticulars. Secondary goals are to trace the structural parameters of
the red population with redshift, compare structure parameters with morphological
classifications and select candidates for kinematic studies. This study is the
structural equivalent of morphological studies where the galaxy's surface brightness
profile is used to classify systems rather than the Hubble scheme.
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                                                10683(  1) - 04/05/05 12:36  - [  2]

            Summary Form for Proposal  10683

  Item                         Used in this proposal
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  Proposal Category            AR
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