10279(  1) - 04/02/04 10:39  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      10279
                                                       Version: 1
                                                       Check-in Date: 02-Apr-2004
                                                                      10:39:22

1.Proposal Title:
A Comprehensive Study of Interstellar Depletions
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2. Proposal For  3. Cycle  4. Parallel Pointing Tolerance
AR               13        <none>
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5. Investigators
                                                                                     Contact?
    PI: Dr. Edward B. Jenkins             Princeton University
   CoI: Dr. Jason X. Prochaska            University of California - Santa Cruz         N

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6. Abstract

We propose to analyze interstellar gas-phase abundances of Ga, Sn, Pb, B, S by
measuring their absorption features in the spectra of stars observed in SNAP survey
programs 8241, 8662 and 9434 (plus other programs that have had archive data
released to the public). The lines of Pb II and B II are extremely weak, so stars
will be grouped into cases having different levels of general depletion and then
within each category the spectra will be coadded to enhance the detectability of the
lines. These data will be combined with results derived by S. Cartledge and
coworkers on O and Kr, plus data soon to be published for Ge, Cu, Mg, Mn, Ni and P,
in order to understand the general behavior of depletions of atoms onto dust grains
under different conditions, using a new analysis technique developed by Jenkins
(2003). A better knowledge of the systematics of depletions will be beneficial to
studies of the compositions of dust grains and will also aid investigations of total
element abundances in distant damped L-alpha (DLA) systems seen in the spectra of
quasars recorded by ground-based telescopes.
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                                                10279(  1) - 04/02/04 10:39  - [  2]

            Summary Form for Proposal  10279

  Item                         Used in this proposal
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  Proposal Category            AR
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