8762(  1) - 12/30/99 13:05  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8762
                                                       Version: 1
                                                       Check-in Date: 30-Dec-1999
                                                                      12:32:50

1.Proposal Title:
The Fundamental Plane of Cluster Ellipticals at z = 0.18: Establishing the Local
Baseline
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2. Proposal For  3. Cycle
AR               9
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4. Investigators
                                                                                     Contact?
    PI: S. George Djorgovski              California Institute of Technology
   CoI: Dr. Michael Pahre                 Smithsonian Astrophysical Observatory         N
   CoI: Dr. Gordon Squires                California Institute of Technology            N
   CoI: Dr. Pieter van Dokkum             California Institute of Technology            N
   CoI: Dr. Ashish Mahabal                California Institute of Technology            N

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5. Abstract

The process of assembling of galaxies into rich clusters may leave distinctive
signatures in the stellar populations and morphological mix that depend on position
in the cluster, and evolve with redshift. We propose to study the properties of
galaxies in the core and halo of the galaxy cluster A1689 at z = 0.18 using a
combination of HST optical, emphmosaic imaging (archival), ground-based optical and
IR imaging (already obtained), and Keck medium resolution spectroscopy. This study
will alleviate systematic uncertainties in the very local studies of the cluster
galaxy population (in Coma) and form a bridge to the results from intermediate- to
high-z systems. As a function of local galaxy density within each cluster, we will
study the projections of the Fundamental Plane correlations (the optical-infrared
color-magnitude relation and the radius-luminosity relation), the IR luminosity
function, and the changing morphological mix. Keck spectroscopy will play a vital
role in efficiently determining velocities and rotation curves for cluster members.
The images will also be searched for extremely-red galaxies---which could represent
high-redshift elliptical (z ~ 1) or star-forming (z > 4) galaxies lensed by the rich
clusters. emphThis study is unique in that both the ground-based IR imaging and the
HST optical imaging mosaic a wide-field, thereby allowing for the simultaneous study
of galaxies in the core and the halo of the cluster.
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                                                8762(  1) - 12/30/99 13:05  - [  2]

            Summary Form for Proposal  8762

  Item                         Used in this proposal
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  Proposal Category            AR
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