9909(  1) - 04/04/03 10:11  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      9909
                                                       Version: 1
                                                       Check-in Date: 04-Apr-2003
                                                                      10:11:35

1.Proposal Title:
The Impact of Infall and Outflow Motions on the Circumstellar Evelope of Young Stars
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2. Proposal For  3. Cycle
AR               11
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4. Investigators
                                                                                     Contact?
    PI: Hector Arce                       California Institute of Technology
   CoI: Dr. Nuria Calvet                  Smithsonian Institution Astrophysical         N
                                          Observatory
   CoI: Dr. Anneila Sargent               California Institute of Technology            N

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5. Abstract

We propose to combine the complementary information obtained from HST (WFPC2 and
NICMOS) archival images and OVRO millimeter array observations of protostars to
obtain the best information available on the physical and dynamical properties of
infalling circumstellar envelopes and the outflow-envelope interaction. The HST
images of protostellar nebulae probe the dust component of the envelope, and are the
best tracers of the geometry of the cavities in the envelope down to regions very
close to the central source. Interferometric molecular line observations probe the
gas component, which constitutes most of the mass, and provide kinematic information
that directly reflects the energetics and directions of the outflows, and the
distribution of the infalling gas. The information provided by these two sets of
data will be analyzed consistently with scattered light models of protostellar
envelopes of different geometries in which cavities due to infall and/or winds with
different morphologies and strength have been carved. Only by combining the HST and
OVRO data we can obtain the (unprecedented) information essential to understanding
the star formation process.
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                                                9909(  1) - 04/04/03 10:11  - [  2]

            Summary Form for Proposal  9909

  Item                         Used in this proposal
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  Proposal Category            AR
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