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    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID 3648c
                                                       Report Date: 09-May-96:18:46
                                                       Version: **********
                                                       Check-in Date: **********

1.Proposal Title:
IMAGING OF BL LAC HOST GALAXIES AND ENVIRONMENTS
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2. Scientific Category   3. Proposal For  4. Proposal Type        5. Continuation ID
QUASARS & AGN               GO                                       <none>
Sub Category
BL LACS
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6. Principal Investigator   Institution                    Country    Telephone
 Chris D. Impey             UNIVERSITY OF ARIZONA          USA        602-621-6522

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7. Abstract
We propose to take deep Planetary Camera images of 4 BL Lac objects in the I(795LP)
filter. Image deconvolution techniques will be used to a) measure luminosities and
basic morphological information for the nebulosity, b) determine the degree of
centering of the AGN on the nebulosity, and c) study the cluster environment of the
AGN. The BL Lac objects are selected from complete X-ray and radio-selected samples
and lie in the redshift range 0.34 < z < 0.55.  We will derive structural
information unobtainable from the ground, and will be able to measure evolutionary
effects by comparison with ground-based data obtained for objects at lower redshift.
There is good evidence that the continuum properties of BL Lac objects are affected
by two quite distinct physical mechanisms: relativistic beaming and gravitational
lensing. If beaming models are generally applicable, the data will yield a test of
the parent population of BL Lacs (the misdirected jets) via the distribution of host
galaxy luminosities and morphologies. If (micro)lensing is common, it will manifest
itself as off-centered nebulosity around the AGN, and an inferred host galaxy that
is too luminous to be at the redshift of the BL Lac object. Either way, we will be
able to detect cosmic evolution in the environment, or differences between X-ray and
radio- selected BL Lacs.
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9. Est obs time (hours) pri: 11.50    par: 0       10. Num targs pri: 4      par: 0
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11. Instruments requested:  WF/PC
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                                                                  Page   2
I. GENERAL FORM    Proposal 3648c
PI:  Chris D. Impey
Proposal Title:
IMAGING OF BL LAC HOST GALAXIES AND ENVIRONMENTS
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1. Proposers:
Proposers                        Institution                       Country       ESA
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Pi Chris D. Impey                UNIVERSITY OF ARIZONA             USA
 Buell T. Jannuzi                INSTITUTE FOR ADVANCED STUDY      USA
 Richard F. Green                NATIONAL OPTICAL ASTRONOMY        USA
                                 OBSERVATORIES
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  3. Description of proposed observations.
  Four target BL Lac objects are to be observed, with the PC and the 795LP (I)
 filter. A short exposure of a nearby bright star will be made before observing
 each BL Lac object, used as a local PSF calibrator. The scientific goals of this
 project require an excellent understanding of the PSF, beyond that provided by
 the monitoring program. The PSF stars are taken from the Guide Star Photometric
 Catalog, and are all within three degrees of their repsective BL Lac objects.
 Each BL Lac object is to be observed for between six and eight 15 minute
 exposures, using pre-flash, but with no automatic splitting of the exposures due
 to cosmic ray considerations. Observations of the BL Lac and local PSF star
 should be made sequentially, but there is no time constraint between the
 observations of different BL Lacs. PC6 default position is to be used for all
 exposures.
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  4. Justification of need for HST observations.
  ST observations are required in order to study the morphology of the host galaxy
 of BL Lac objects at moderate redshift, requiring spatial resolution not
 obtainable from the ground.
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  5. Description of special scheduling requirements.
  Observations of each BL lac objects and its local PSF star calibrator should be
 made sequentially, to ensure the most accurate calibration of the PSF possible.
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  7. Data reduction and analysis plans.
  Data reduction and analysis will be performed at both the Institute for Advanced
 Study and at Steward Observatory.
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 10. Resources to be supplied by investigator's institution(s).
  Computing support will be provided by both IAS and Steward Observatory, and
 graduate student support will come from Steward.
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11. Address Information
Name:  CHRIS D. IMPEY                                      Category: PI
Institution: UNIVERSITY OF ARIZONA
Address:  STEWARD OBSERVATORY
          UNIVERSITY OF ARIZONA
City: TUCSON                                    State: AZ
Zip Code: 85721                                 Country: USA
Telephone: 602-621-6522
Telex (or e-mail): 467175
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TARGET LIST    a) Fixed Targets                                                                    ID = 3648c            [  3]
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 1 |     2      |           3           |              4             |  5     |   6    |  7  |              8
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Tar|   Target   |         Target        |            Target          |Coord   | Radial |Acqui|FLX|     Flux data
No |    Name    |       Description     |           Position         |Eqnx    |  Vel.  |Prblm|REF|
   |            |                       |                            |        |        |     |   |
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1   0823+033-    J, 704                  RA = 08H 26M 31.70S +/-      1950                    1   V = 13.7 +/- 0.2
    CALIB                                0.05S,
                                         DEC = +06D 09' 23.0" +/-
                                         0.5"
     Comments: PSF CALIBRATOR FOR 0823+033
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2   0823+033 PKS E, 316                  RA = 08H 23M 13.56S +/-      1950     Z=0.506        1   V = 18.0 +/- 0.2
                                         0.02S,
                                         DEC = +03D 19' 15.7" +/-
                                         0.2"
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3   0828+493-    J, 704                  RA = 08H 28M 30.20S +/-      1950                    1   V = 13.9 +/- 0.2
    CALIB                                0.05S,
                                         DEC = +48D 29' 29.0" +/-
                                         0.5"
     Comments: PSF CALIBRATOR FOR 0828+493
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4   0828+493 PKS E, 316                  RA = 08H 28M 47.94S +/-      1950     Z=0.548        1   V = 18.5 +/- 0.2
                                         0.02S,
                                         DEC = +49D 23' 33.4" +/-
                                         0.2"
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5   1407+599-    J, 704                  RA = 13H 55M 02.70S +/-      1950                    1   V = 14.1 +/- 0.2
    CALIB                                0.05S,
                                         DEC = +58D 49' 40.0" +/-
                                         0.5"
     Comments: PSF CALIBRATOR FOR 1407+599
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6   1407+599 MSS E, 316                  RA = 14H 07M 50.75S +/-      1950     Z=0.495        1   V = 17.1 +/- 0.2
                                         0.1S,
                                         DEC = +59D 53' 48.8" +/- 1"
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7   1757+705-    J, 704                  RA = 18H 07M 20.90S +/-      1950                    1   V = 13.9 +/- 0.2
    CALIB                                0.05S,
                                         DEC = +71D 29' 31.0" +/-
                                         0.5"
     Comments: PSF CALIBRATOR FOR 1757+705
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8   1757+705 MSS E, 316                  RA = 17H 57M 48.70S +/-      1950     Z=0.407        1   V = 17.1 +/- 0.2
                                         0.1S,
                                         DEC = +70D 33' 48.8" +/- 1"
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EXPOSURE LOGSHEET                                                                                  ID = 3648c            [  4]
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 1      |   2   |      3    |  4   |   5   |   6   |    7   |   8   |       9       |10 |   11  |   12    |13 |14|        15
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  Line  |  Seq  |   Target  |Instr | Oper. | Aper  |Spectral|Central|   Optional    |Num|  Time |   S/N   |Flx|Pr|     Special
 Number | Name  |    Name   |Config| Mode  |or FOV |Element |Waveln.|  Parameters   |Exp|       |Rel. Time|Ref|  |   Requirements
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1                0823+033-   PC     IMAGE   P6      F785LP           PRE-FLASH=YES   1   0.60S             1   1  CYCLE 2 / 1-8
                 CALIB                                                                                            PCS MODE F / 1-8
                                                                                                                  SEQ 1-2 NO GAP
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2                0823+033    PC     IMAGE   P6      F785LP           PRE-FLASH=YES   7   900S              1   1
                                                                     CR-SPLIT=NO
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3                0828+493-   PC     IMAGE   P6      F785LP           PRE-FLASH=YES   1   0.70S             1   3  SEQ 3-4 NO GAP
                 CALIB
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4                0828+493    PC     IMAGE   P6      F785LP           PRE-FLASH=YES   8   900S              1   3
                                                                     CR-SPLIT=NO
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5                1407+599-   PC     IMAGE   P6      F785LP           PRE-FLASH=YES   1   1.00S             1   2  SEQ 5-6 NO GAP
                 CALIB
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6                1407+599    PC     IMAGE   P6      F785LP           PRE-FLASH=YES   7   900S              1   2
                                                                     CR-SPLIT=NO
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7                1757+705-   PC     IMAGE   P6      F785LP           PRE-FLASH=YES   1   0.70S             1   4  SEQ 7-8 NO GAP
                 CALIB
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8                1757+705    PC     IMAGE   P6      F785LP           PRE-FLASH=YES   6   900S              1   4
                                                                     CR-SPLIT=NO
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            Summary Form for Proposal 3648c                                                                              [  5]

  Item                          Used in this proposal
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  Configurations                PC
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  Opmodes                       IMAGE
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  Optional Parameters           PRE-FLASH=YES CR-SPLIT=NO
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  Proposal for                  GO
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  S/C Hours                     11.50
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  Scientific Category           QUASARS & AGN
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  Scientific Sub-category       BL LACS
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  Special Requirements          CYCLE 2 / 1-8; PCS MODE F / 1-8; SEQ 1-2 NO GAP SEQ 3-4 NO GAP SEQ 5-6 NO GAP SEQ 7-8 NO GAP
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  Spectral Elements             F785LP
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  Target Names                  0823+033-CALIB 0823+033 PKS 0828+493-CALIB 0828+493 1407+599-CALIB 1407+599 MSS 1757+705-CALIB
                                1757+705
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