8375(  2) - 12/18/98 16:52  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8375
                                                       Version: 2
                                                       Check-in Date: 18-Dec-1998
                                                                      16:50:50

1.Proposal Title:
ACCRETION DISKS AND DUST DISKS IN ACTIVE ELLIPTICAL GALAXIES
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2. Proposal For  3. Cycle
AR               8
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4. Investigators
                                                                                     Contact?
    PI: Anne Kinney                       Space Telescope Science Institute
   CoI: Dr. Robert Antonucci              University of California at Santa Barbara     N
   CoI: Dr. James Pringle                 Institute of Astronomy - Cambridge            N
   CoI: Dr. Henrique Schmitt              Space Telescope Science Institute             N
   CoI: Dr. James Ulvestad                National Radio Astronomy Observatory          N

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5. Abstract

We aim here to study the relation between optical/radio nuclear activity and
resolvable dust/gas disks in active ellipticals. We will do this by analyzing a
complete, unbiased sample of 112 galaxies chosen on a nearly isotropic property, the
diffuse radio flux at 178 MHz. In order to understand the significance of the
detected dust in the active ellipticals, we will also analyze a control sample of
135 normal ellipticals matched in starlight luminosity and central surface
brightness for comparison. The inner dust structures which probe the effects
described here appear on very small scales and generally cannot be observed from the
ground. The relative position angle between the radio axis and the dust disk serves
as a powerful diagnostic; the orientation of the outer dust disk has the potential
to reveal the history of a triggering merger, while the orientation of the innermost
dust disk reveals the structure of the accretion disk on ~ 10-100 pc scale. Finally,
the radio jet indicates the innermost axis which is generated on scales of ~ 100 R_G
or less. With a sample that includes FRI's, FRII's (with luminous active nuclei and
``optically dull"), and normal elliptical galaxies, we can test predictions for the
causes of activity, current ideas about the dynamics of the gas/dust involved in
mergers, and probe the physics of the resulting accretion disks.
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  Data Distribution

  Paper Products:  NO
  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
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                                                8375(  2) - 12/18/98 16:52  - [  2]

            Summary Form for Proposal  8375

  Item                         Used in this proposal
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  Proposal Category            AR
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