8361(  2) - 12/18/98 16:47  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8361
                                                       Version: 2
                                                       Check-in Date: 18-Dec-1998
                                                                      16:45:48

1.Proposal Title:
The Bulge Properties and Fueling Mechanisms of Nearby AGNs
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2. Proposal For  3. Cycle
AR               8
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4. Investigators
                                                                                     Contact?
    PI: Alex Filippenko                   University of California at Berkeley
   CoI: Dr.  Luis Ho                      Carnegie Observatories                        N
   CoI: Prof. Wallace Sargent             California Institute of Technology            N

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5. Abstract

We recently completed an optical spectroscopic survey of nearby galaxies that has
shown that a substantial fraction of all galaxies, especially those of early Hubble
type, exhibit active galactic nuclei. Under the assumption that these are powered by
supermassive black holes (SMBHs), we conclude that SMBHs appear to be common
constituents of many, but not necessarily all, elliptical and bulge-dominated
galaxies. We wish to investigate why some galaxy bulges seem more conducive than
others to hosting SMBHs, or at least SMBHs with associated activity. We propose to
conduct a study of near-IR (NIR) archival NICMOS images of galaxies from a
representative sample of ``active'' and ``normal'' disk galaxies (S0--Sc) selected
from our spectroscopic survey in order to (1) quantify the bulge luminosity and (2)
perform a comparative study of the structural parameters of the bulges detected. The
brightness profiles of the central regions can be quantified much more reliably in
the NIR than in the optical because of the lower dust extinction and reduced
sensitivity to nuclear spiral arms and star-forming regions. In addition, we will
use the images to search for small-scale nuclear bars, either stellar or gaseous, as
well as nuclear star clusters, both of which have been suggested as possible
mechanisms for fueling the central engine.
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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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                                                8361(  2) - 12/18/98 16:47  - [  2]

            Summary Form for Proposal  8361

  Item                         Used in this proposal
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  Proposal Category            AR
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