7526(  1) - 12/14/96 00:30  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      7526
                                                       Version: 1
                                                       Check-in Date: 13-Dec-1996
                                                                      18:15:27

1.Proposal Title:
FeII Emission in Quasars
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2. Scientific Category   3. Proposal For  4. Cycle
AGN/QUASARS                 AR               7
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5. Investigators
                                                                                     Contact?
    PI: Gary Ferland                      University of Kentucky
   CoI: Ekaterina Verner                  University of Kentucky                        N
   CoI: Kirk Korista                      University of Kentucky                        N
   CoI: Dmitri Verner                     University of Kentucky                        N
   CoI: Jack Baldwin                      Cerro Tololo Inter-American Observatory       N
   CoI: Fred Hamann                       University of California-San Diego            N

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6. Abstract

FeII emission is observed from a wide variety of astronomical objects, including
protostellar disks, novae, supernovae, and quasars, but it has been notoriously hard
to interpret because of the great complexity of the Fe^+ energy level structure. We
are in the middle of a long term program to fully simulate the physical conditions
within FeII-emitting gas and then predict the resulting spectrum. This involves the
adaptation and encapsulation of vast amounts of atomic data, and its incorporation
into the photoionization code Cloudy. Our approved Cycle 6 archive proposal used HST
observations of the sharp lined strong FeII-emitting stars RR Tel and Eta Carinae,
and the Seyfert galaxy I Zw 1, to validate the completeness and predictions of the
model atom. Here we request archival HST observations of 56 low-redshift quasars to
extend our Cycle 6 work to the family of AGN. Our long term goal is to deduce iron
abundances from FeII emission in high redshift quasars. It is doubtful that the
range of FeII equivalent widths is due to abundances alone; cloud properties must
also contribute to line visibility. The HST observations will be used together with
optical data and extensive grids of photoionization calculations to understand what
controls the visibility of FeII emission, and to quantify what it says about iron
abundances. When complete this will result in a chronometer measuring the redshift
when the universe passed through an age of 1 Gyr, thus constraining several
cosmological parameters.
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  Data Distribution

  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:                                                              ,
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                                                7526(  1) - 12/14/96 00:30  - [  1]

            Summary Form for Proposal  7526

  Item                         Used in this proposal
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  Proposal Category            AR
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  Scientific Category          AGN/QUASARS
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