9553(  3) - 07/02/02 10:32  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      9553
                                                       Version: 3
                                                       Check-in Date: 02-Jul-2002
                                                                      10:31:27

1.Proposal Title:
The Birth and Evolution of Superbubbles
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2. Proposal For  3. Cycle
AR               11
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4. Investigators
                                                                                     Contact?
    PI: Jesus Maiz-Apellaniz              Space Telescope Science Institute
   CoI: Dr. John W. MacKenty              Space Telescope Science Institute             N
   CoI: Prof. Colin A. Norman             The Johns Hopkins University                  N
   CoI: Dr. Keiichi Wada                  National Astronomical Observatory             N
   CoI: Dr. Eduardo Telles                Observatorio Nacional                         N
   CoI: Dr. Henri Plana                   Observatorio Nacional                         N

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5. Abstract

We propose to analyze all the nebular WFPC2 observations of massive young clusters
(MYCs) within 10 Mpc in order to understand the interaction with the surrounding
medium which leads to the creation of superbubbles. In a previous analysis we
detected a discrepancy between the measured and the expected size distribution of
superbubble sizes around a small sample of nearby MYCs. We propose to measure the
diameters of the hot cavities created around the clusters by the stellar winds and
supernovae for all the objects in this extended sample. The data will be combined
with ground-based high- spectral-resolution spectroscopic observations of a
subsample of the clusters in order to relate the cavity size to the velocity
dispersion of the warm gas. Our final goals are: (i) to verify the existence of the
discrepancy between the expected and the measured cavity size distribution and to
find an explanation for it, and (ii) to discern which is the energy source that
mantains the supersonic velocity dispersion of the warm gas in Giant H, ii Regions:
gravity, stellar winds, radiation, or a combination of them. In order to do that we
will generate 3-D hydrodynamic simulations which include the effects of gravity and
radiation and compare them with the observed data.
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                                                9553(  3) - 07/02/02 10:32  - [  2]

            Summary Form for Proposal  9553

  Item                         Used in this proposal
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  Proposal Category            AR
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