10668(  1) - 04/05/05 12:27  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      10668
                                                       Version: 1
                                                       Check-in Date: 05-Apr-2005
                                                                      16:27:39

1.Proposal Title:
The Theory of Multiscale Gravitational Lensing
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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. Charles R. Keeton             Rutgers the State University of New Jersey
   CoI: Dr. Bhuvnesh Jain                 University of Pennsylvania                    N
   CoI: Mr. Greg Dobler                   University of Pennsylvania                    N

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6. Abstract

Strong gravitational lensing probes the mass distributions of distant galaxies on
scales from tens of kiloparsecs (dark matter halos and "macrolensing") through
parsecs (dark matter substructure and "millilensing") all the way down to individual
stars ("microlensing"). Wonderful data are now available, thanks in large part to
HST. However, the theoretical understanding of lensing on different scales is much
less mature, which has complicated efforts to interpret the data. We have begun a
comprehensive theoretical study of multiscale lensing, to develop a formalism that
will enable us both to interpret existing data and to inspire and guide new
observations. In this proposal, we specifically seek to develop the first code that
simultaneously includes macro-, milli-, and microlensing. We will then use it to:
(1) Find clear observational signatures that reveal the scale(s) being probed in
data, and then resolve the debate about whether millilensing truly reveals Cold Dark
Matter substructure. (2) Show how observations at different scales can constrain the
mass function of stars in lens galaxies, and apply the method to existing HST data
for seven distant galaxies. (3) Examine non-linearities that link micro-, milli-,
and macrolensing, and use the combined analysis to open a new window on dark matter
studies with strong lensing. We will also make the code available to the community
as part of PI Keeton's public lensing software.
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                                                10668(  1) - 04/05/05 12:27  - [  2]

            Summary Form for Proposal  10668

  Item                         Used in this proposal
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  Proposal Category            AR
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