6720(  4) - 12/04/96 14:51  - [  0]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      6720
                                                       Version: 4
                                                       Check-in Date: 04-Dec-1996
                                                                      14:42:57

1.Proposal Title:
The Evolution of Radio-Loud Quasars II
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2. Scientific Category   3. Proposal For  4. Cycle
AGN                         GO               6
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5. Investigators
                                                                                     Contact?
    PI: Matthew Lehnert                   Institute of Geophysics and Planetary
                                          Physics
   CoI: Wil van Breugel                   Institute of Geophysics and Planetary         N
                                          Physics, LLNL, 7000 East Ave., L-413,
   CoI: Vijay Kapahi                      National Center for Radio Astrophysics,       N
                                          TIFR, Pune 411 007, India
   CoI: Timothy Heckman                   Dept. of Physics & Astron, Johns Hopkins      N
                                          University, Baltimore, MD 21218
   CoI: Patrick McCarthy                  Carnegie Observatories, 813 Santa Barbara     N
                                          St., Pasadena, CA 91101

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6. Abstract

The first HST results from our cycle 5 mini-survey of a carefully selected sample of
radio quasars show dramatic evolution in the morphologies and luminosities of their
host galaxies between 0.3 < z < 2.7. Our complete sample is unique in that the
quasars span a range of radio properties, are uniformly spread in look-back time,
are imaged at the same (2000 Angstrom) restframe, and to approximately the same
(observed) limiting surface brightness. We believe that our careful selection is
crucial for investigating the properties and evolution of quasar host galaxies and
our early results seem to bear this out. In view of the many unknown factors which
may govern quasar and quasar-host evolution, and the already clear evidence for
strong evolutionary effects (in short, 1 - 2 orbit exposures .), we propose to
complete our original request to observe all 20 quasars from our sample. This will
provide us with a sufficient number of quasars to allow some confidence in general
conclusions and, in particular, to search for evolutionary differences/connections
between the various radio source classes. When compared with the sofar much better
studied radio galaxies in other HST programs, we will be able to address the
important question of whether radio-loud quasars and radio galaxies are members of
the same parent population as is fashionable in the AGN unification schemes, and
investigate how the hosts of luminous AGN have evolved over the epochs where
luminous quasars have become virtually extinct.
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  Observations Description
  ------------------------

     Quasar Sample Our quasars all have redshifts of between 0.276 and 2.667 and are
     chosen from the Molonglo Reference Catalog of radio sources. We have split the
     sample into four redshift bins (z<0.7, 0.7<z<1.25, 1.25<z<2.0, and 2.0<z<2.7)
     and all the bins are of approximately equal size in units of log(1+z) evolution
     with epoch is usually parameterized as (1+z)^Beta. In each of these four bins
     we have chosen 5 quasars which represent the full range of radio properties
     i.e., two have compact radio sizes (l_r \\ltwid2'') and steep radio spectral
     index (alpha_0.4-1.4 \\ GHz<-0.7), two have extended radio emission (radio
     sizes ~ 2'' - 100'') and steep radio spectra, and one that is a compact flat
     spectrum source (alpha_0.4-1.4 \\ GHz > -0.5). The current request will
     complete our scheduled Cycle 5 program, which was reduced by 50\\% from 20 to
     10 targets. In view of the the already clear evidence for strong evolutionary
     effects (in short, 1 - 2 orbit exposures .), and the many unknown factors which
     may govern quasar and quasar-host evolution, we propose to complete our
     original request to observe all 20 quasars from our sample. 0.1in Continuum
     Imaging Our choice of continuum filter is dictated by three criteria. First,
     the filter bandpass should exclude bright emission lines. Second, the filter
     should be among the most efficient broad- band filters available on the WFPC2
     and also correspond roughly to common ground-based filters to yield `real'
     magnitudes. Third, the central wavelength should correspond roughly to a
     uniform rest wavelength in all the quasars over the whole redshift range. The
     most suitable choices are F336W (~U, for quasars with z<0.7), F439W (~B, for
     quasars with 0.7<z<1.25), F555W (~V, for quasars with 1.25<z<2.0) and F675W
     (~R, for quasars with 2.0<z<2.7). These four filters will allow us to measure
     the morphology and brightness of the extended continuum emission at central
     rest-frame wavelengths of about 1800-2500Angstrom \\ for all quasars in our
     sample. The band-pass does include CIIILambda1909 for many of the quasars, but
     spectroscopic observations of the fuzz around radio-loud quasars show that this
     line is extremely weak there: <= few\\% of LyAlpha (Heckman et al 1992b). Thus,
     there is only significant CIII emission in the quasar broad- line region and
     not in the host galaxy. Depending on the redshift of the quasar, we will
     observe it through either the F336W, F439W, F555W, or F675W filter using the
     Planetary Camera. Attempting to somewhat compensate for the relative
     efficiencies of the filters (the blue filters, F336W and F439W, are about a
     factor 4 less efficient than the red filters, F555W and F675W) we will observe
     a quasar for two orbits if the appropriate filter is F336W or F439W, or for one
     orbit if the appropriate filte is F555W or F675W. Considering the great demand
     for the available HST observing time, such a distribution of exposure time is a
     reasonable compromise between the number of orbits requested and still being
     able to achieve our scientific goals. Dynamic range considerations will limit
     the exposure times to ~ 10 minutes in the red filters F555W and F675W and
     approximately 20 minutes in the two blue filters, F336W and F439W. We stress
     the importance of not saturating the nucleus of the quasar. For example, in
     Figure 1 we show the image of MRC0029-271 taken with the PC through the F336W
     filter. The emission from the host is extended only over about 15-20 PC pixels.
     If the nucleus is saturated (even over a small number of pixels), scaling the
     PSF to subtract the nucleus becomes very difficult and detection of marginally
     extended emission becomes impossible. When the nucleus is not saturated (as we
     always attempt to do in our programs), nuclear subtraction is relatively
     straight-forward and relatively accurate photometry and determination of ``near
     -nuclear'' morphological information can be obtained. After allowing for guide
     star acquisition and setup time we will be able to observe each quasar for ~ 3
     * 10 in one orbit with the red filters and for ~ 2 orbits * 2 exposures/orbit *
     20 minutes/exposure in the blue filters. Total integration times of ~ 40
     minutes through the red filters and ~ 80 minutes in the blue filters, will
     allow us to detect the extended near- nuclear emission and clumpy structure on
     scales of a << 1 kpc (even at the highest redshifts) down to 25.2 magnitudes
     HST PSF^-1 in the F336W filter (the `slowest' filter) for the lowest redshift
     quasars and to 27.7 magnitudes HST PSF^-1 in the F675W (the `fastest' filter)
     for the highest redshift quasars. We emphasize that previous data taken with
     HST on radio galaxies and quasars indicates that these magnitude limits are
     easily deep enough to reveal significant structure near such objects -- see
     Lehnert Etal 1995a,b; Figure 1 in this proposal; Hutchings Etal 1994, ApJ, 429,
     L1; Miley Etal 1992. We therefore request a total of 16 orbits to image a 10
     more quasars to complete a statistically significant sample of 20 quasars with
     a range of redshift and radio properties to determine their rest-frame UV
     magnitudes and morphologies. In Cycle 4, we note that there is a program to
     take ``snap shots'' of 3CR radio sources, including some quasars (Sparks PI).
     While this is a valuable program to investigate some of the issues raised in
     the justification, we note that this snap shot program has short exposure times
     and that the images of all of the sources, regardless of redshift, are taken
     through the same filter. Our images will go deeper and have the advantage that
     they will image all 20 of the quasars in the final sample at nearly the same
     rest wavelength. While the two programs are in some sense complimentary, we
     emphasize that many of the astrophysically important issues raised in the
     justification can only be investigated using the observational strategy of this
     proposal.

  Real Time Justification
  -----------------------

     We do not have any special requirements. We are pursuing several types of
     supporting observations for this and our other HST programs on the hosts and
     environments of quasars, including deep spectroscopy and spectropolarimetry
     using the Keck 10m telescope and we are taking advantage of the new generation
     of 4m class telescopes with sub-arcsec imaging capabilities (e.g. WIYN, ESO
     NTT, etc) for multi-band (optical, IR) quasars surveys, and we are planning to
     obtain further high quality, high resolution radio images of these targets
     using the VLA.

  Calibration Justification
  -------------------------


  Additional Comments
  -------------------

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  Data Distribution

  Media:           8MM
  Blocking Factor: 10
  Ship To:         Matt Lehnert*Sterrewacht Leiden*2300 RA
                   Leiden*The Netherlands
  Ship Via:        UPS
  Email:                                                              ,
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                                                6720(  4) - 12/04/96 14:51  - [  1]

TARGET LIST    a) Fixed Targets
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Tar|   Target   |         Target        |            Target              |Coord   | Radial |             Flux data
No |    Name    |       Description     |           Position             |Eqnx    |  Vel.  |
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1   MRC0040-208  Galaxy, Quasar          RA=00H 40M 29.20S +/- 0.03S,     B1950.0  Z=0.656  B = 19.0
                                         DEC=-20D 53' 38.9" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

2   MRC2024-217  Galaxy, Quasar          RA=20H 24M 09.21S +/- 0.03S,     B1950.0  Z=0.459  B = 20.6
                                         DEC=-21D 46' 13.8" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

3   MRC1349-265  Galaxy, Quasar          RA=13H 49M 20.94S +/- 0.03S,     B1950.0  Z=0.802  B = 19.9
                                         DEC=-26D 34' 41.0" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

4   MRC2156-245  Galaxy, Quasar          RA=21H 56M 35.76S +/- 0.03S,     B1950.0  Z=0.962  B = 20.6
                                         DEC=-24D 32' 16.0" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

5   MRC1301-251  Galaxy, Quasar          RA=13H 01M 32.30S +/- 0.03S,     B1950.0  Z=0.952  B = 21.0
                                         DEC=-25D 08' 31.5" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

6   MRC0941-200  Galaxy, Quasar          RA=09H 41M 30.20S +/- 0.03S,     B1950.0  Z=0.715  B = 18.6
                                         DEC=-20D 05' 45.0" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

7   MRC1106-227  Galaxy, Quasar          RA=11H 06M 43.35S +/- 0.03S,     B1950.0  Z=1.875  B = 20.0
                                         DEC=-22D 45' 28.8" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

8   MRC2210-257  Galaxy, Quasar          RA=22H 10M 14.13S +/- 0.03S,     B1950.0  Z=1.831  B = 18.3
                                         DEC=-25D 44' 22.4" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

9   MRC1025-264  Galaxy, Quasar          RA=10H 25M 49.14S +/- 0.03S,     B1950.0  Z=2.665  B = 17.9
                                         DEC=-26D 28' 55.7" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

10  MRC2158-206  Galaxy, Quasar          RA=21H 58M 40.80S +/- 0.03S,     B1950.0  Z=2.272  B = 19.5
                                         DEC=-20D 40' 03.4" +/- 0.5"

   Epoch of Position    RA proper motion (seconds of time/yr)    DEC Proper Motion (arcsec/yr)    Annual Parallax (arcsec)
   B1950.0              0.000                                    0.000                            0.000

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Visit: 01
     Visit Requirements:  ORIENT 290D TO 190D
     On Hold Comments:    <none>
     Additional Comments: Bright star at PA=242D, 60" from Target


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC0040-208 WFPC2  IMAGE   PC1     F336W    3344                                      1   2400 S
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2        MRC0040-208 WFPC2  IMAGE   PC1     F336W    3344                                      1   2600 S  POS TARG 0.5, 0.5
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Visit: 02
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC2024-217 WFPC2  IMAGE   PC1     F336W    3344                                      1   2400 S
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2        MRC2024-217 WFPC2  IMAGE   PC1     F336W    3344                                      1   2600 S  POS TARG 0.5, 0.5
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Visit: 03
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC0941-200 WFPC2  IMAGE   PC1     F439W    4300                                      1   2400 S
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2        MRC0941-200 WFPC2  IMAGE   PC1     F439W    4300                                      1   2600 S  POS TARG 0.5, 0.5
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Visit: 04
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC1349-265 WFPC2  IMAGE   PC1     F439W    4300                                      1   2400 S
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2        MRC1349-265 WFPC2  IMAGE   PC1     F439W    4300                                      1   2600 S  POS TARG 0.5, 0.5
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Visit: 05
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC2156-245 WFPC2  IMAGE   PC1     F439W    4300                                      1   2400 S
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2        MRC2156-245 WFPC2  IMAGE   PC1     F439W    4300                                      1   2600 S  POS TARG 0.5, 0.5
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Visit: 06
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC1301-251 WFPC2  IMAGE   PC1     F439W    4300                                      1   2400 S
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2        MRC1301-251 WFPC2  IMAGE   PC1     F439W    4300                                      1   2600 S  POS TARG 0.5, 0.5
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Visit: 07
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC1106-227 WFPC2  IMAGE   PC1     F555W    5407                                      1   1600 S
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2        MRC1106-227 WFPC2  IMAGE   PC1     F555W    5407    CR-SPLIT=NO                       1   700 S
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Visit: 08
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC2210-257 WFPC2  IMAGE   PC1     F555W    5407                                      1   1600 S
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2        MRC2210-257 WFPC2  IMAGE   PC1     F555W    5407    CR-SPLIT=NO                       1   700 S
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Visit: 09
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC1025-264 WFPC2  IMAGE   PC1     F675W    6714                                      1   1600 S
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2        MRC1025-264 WFPC2  IMAGE   PC1     F675W    6714    CR-SPLIT=NO                       1   700 S
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Visit: 10
     Visit Requirements:  <none>
     On Hold Comments:    <none>
     Additional Comments: <none>


Exposures
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Exposure|   Target  |Instr | Oper. | Aper  |Spectral|Central|             Optional            |Num|  Time |       Special
 Number |    Name   |Config| Mode  |or FOV |Element |Waveln.|            Parameters           |Exp|       |     Requirements
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1        MRC2158-206 WFPC2  IMAGE   PC1     F675W    6714                                      1   1600 S
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2        MRC2158-206 WFPC2  IMAGE   PC1     F675W    6714    CR-SPLIT=NO                       1   700 S
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            Summary Form for Proposal  6720

  Item                         Used in this proposal
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  Configurations               WFPC2
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  Opmodes                      IMAGE
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  Optional Parameters          CR-SPLIT=NO
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  Proposal Category            GO
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  Scientific Category          AGN
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  Special Requirements         ORIENT 290D TO 190D POS TARG 0.5, 0.5
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  Spectral Elements            F336W F439W F555W F675W
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  Target Names                 MRC0040-208 MRC2024-217 MRC0941-200 MRC1349-265 MRC2156-245 MRC1301-251 MRC1106-227 MRC2210-257
                               MRC1025-264 MRC2158-206
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