!   $Id: 5352,v 7.1 1994/07/27 16:58:27 pepsa Exp $

coverpage:

  title_1:         GRAVITATIONAL LENSING STUDIES WITH HST:
    title_2:       DARK MATTER AND HIGH REDSHIFT GALAXIES -- CYCLE4 HIGH
    sci_cat:       GALAXIES & CLUSTERS
    sci_subcat:    CLUSTERS/LENSES
    proposal_for:  GO
    pi_fname:      BERNARD
    pi_lname:      FORT
    pi_inst:       5474
    pi_country:    FRANCE
    pi_phone:      011 - 33 - 61332821
    hours_pri:     15.00
    num_pri:       2
    wf_pc:         Y
! end of coverpage

abstract:

    line_1:        We propose deep multicolour WFC2 imaging of a sample of
    line_2:        gravitationally-lensed `giant arcs' for which extensive
    line_3:        ground-based data has already been secured. High resolution
    line_4:        studies of these systems offer an unique probe of the dark matter
    line_5:        distribution in the lensing clusters as well as of the nature
    line_6:        of background field galaxies at redshifts above one. By resolving
    line_7:        the arcs and their counter-images with HST, mass models
    line_8:        that account for the lensing are much more highly constrained.
    line_9:        This, in turn, will lead to an improved knowledge of the structure
    line_10:       of the distant sources. Ground-based photometry indicates most
    line_11:       arcs are intensely blue star-forming systems. Morphologies will
    line_12:       provide important information on the ancestors of normal galaxies.
    line_13:       Extrapolating the trends found in recent ground-based data, we also
    line_14:       expect to identify many close image pairs in deep HST images.
    line_15:       These pairs are probably highly magnified images of B=28-30
    line_16:       galaxies. The abundance of pairs will place a new constraint
    line_17:       on the galaxy count turnover and hence the epoch of galaxy
    line_18:       formation. Our program is uniquely suited to WFC2 and builds
    line_19:       on a wealth of existing deep ground-based optical/infrared
    line_20:       data.

!
! end of abstract

general_form_proposers:

  lname:           FORT
    fname:         BERNARD
    inst:          5474
    country:       FRANCE
    esa:           Y

!

  lname:           MELLIER
    fname:         YANNICK
    inst:          5474
    country:       FRANCE
    esa:           Y

!

  lname:           SOUCAIL
    fname:         GENEVIEVE
    inst:          5474
    country:       FRANCE
    esa:           Y

!

  lname:           PELLO
    fname:         ROSER
    inst:          5474
    country:       FRANCE
    esa:           Y

!

  lname:           ELLIS
    fname:         RICHARD
    mi:            S
    inst:          8014
    country:       UK
    esa:           Y

!

  lname:           ARAGON-SALAMANCA
    fname:         ALFONSO
    inst:          8014
    country:       UK
    esa:           Y

!

  lname:           MIRALDA-ESCUDE
    fname:         JORDI
    inst:          2280
    country:       USA
    esa:           Y

!

  lname:           SMAIL
    fname:         IAN
    inst:          1590
    country:       USA

!

  lname:           KNEIB
    fname:         JEAN-PAUL
    inst:          5474
    country:       FRANCE
    esa:           Y

!
! end of general_form_proposers block

general_form_text:

  question:        3
    section:       1
    line_1:        Our target list contains 2 lensing systems, each of which has been
    line_2:        well-studied in previous ground-based campaigns. The selected
    line_3:        clusters are : Cl2244-02 and Abell 2390. We require broad-band
    line_4:        WFPC2 images using filters F555W and F814W. F814W samples the
    line_5:        restframe light longward of 4000 A in the distant source
    line_6:        galaxies at highest efficiency, while F555W samples the near uv
    line_7:        restframe. This combination provides a direct comparison of the
    line_8:        distribution of young stars with that of the entire population.
    line_9:        We need individual exposures of 2300 sec to attain an optimal
    line_10:       s/n ratio. For Cl2244-02 we require 4 exposures in filter F555W
    line_11:       and 6 exposures in filter F814W. In the case of Abell 2390,
    line_12:       the optimal number of exposures is 4 in filter F555W and 5 in
    line_13:       filter F814W. A random shift of about 1 arcsec has to be
    line_14:       introduced between successive frames, in order to correct
    line_15:       for the presence of bad pixels and/or other geometrical
    line_16:       features.

!

  question:        4
    section:       1
    line_1:        The largest ground-based telescopes have been pushed to their
    line_2:        observational limits in the detection and analysis of
    line_3:        gravitationally-lensed images. While considerable progress has
    line_4:        been made, the fundamental limitation remains the inability
    line_5:        to resolve fine detail in the giant arcs, as well as to
    line_6:        unambiguously recognise further signatures of lensing such as
    line_7:        the symmetry of close image pairs. The detail found in the
    line_8:        case of AC114 has demonstrated that not only can these
    line_9:        limitations be overcome with HST, but also that a new regime
    line_10:       of lens models can be constructed. Specifically, in favourable
    line_11:       cases such as those clusters selected in this proposal, it
    line_12:       will become possible to distinguish between structure
    line_13:       in the lensing cluster and that inherent in the distant source.

!

  question:        5
    section:       1
    line_1:        The main requirement is that the exposure time should be at
    line_2:        least 2300 sec (1 orbit) in order to attain an optimal s/n. As
    line_3:        the number of exposures is between 4 and 6 for each cluster + filter
    line_4:        configuration, with a random shift between 2 successive exposures
    line_5:        of about 1 arcsec, the exposures should not be splited into shorter
    line_6:        subexposures.

!

  question:        6
    section:       1
    line_1:

!


!

  question:        8
    section:       1
    line_1:

!

  question:        9
    section:       1
    line_1:        One of the Co-I, R. Ellis, has been involved in the following programs:
    line_2:        No. 2269, 4298 ``Galaxy Populations in Intermediate Redshift Clusters''
    line_3:        (GO Cycles 1 and 3, WFC-1) as Co-I, and No. 4072 ``Star Formation Rates in
    line_4:        Distant Cluster Galaxies'' (GTO Cycle 2, FOC) as PI. These are
    line_5:        largely unrelated programs concerned with the morphology and
    line_6:        star-formation characteristics of cluster member galaxies at z=0.3. Some
    line_7:        gravitational lensing phenomena were found unexpectedly in AC114 (GO 2269)
    line_8:        and the nature of the giant arc in Abell 370 is a secondary goal in the
    line_9:        cycle 3 allocation GO 4298 (yet to be taken). However, the choice of clusters
    line_10:       in these proposals was dictated entirely by the extensive ground-based
    line_11:       spectroscopy of the cluster members and the lensing studies proposed
    line_12:       here could not be carried out with these data. The publications resulting
    line_13:       from these programs up to now are: Deep WFPC Imaging of the z=0.3 cluster
    line_14:       AC114, Sharples, R.M., Smail, I., Ellis, R.S., Couch, W.J., Fitchett, M.J.
    line_15:       eds. Benvenuti, P. & Schreier, E., ESO Conference and Workshop
    line_16:       Proceedings 44, 119-126 (1993) and Morphological Studies of the Galaxy
    line_17:       Populations in Distant `Butcher-Oemler' Clusters with HST,
    line_18:       Couch, W.J.,  Ellis, R.S., Sharples, R.M. and Smail, I.,
    line_19:       in ``Observational Cosmology'', eds. Chincarini, G. et al.,
    line_20:       ASP Conference Series, in press.

!

  question:        10
    section:       1
    line_1:        Toulouse and Cambridge University have excellent computing facilities
    line_2:        based on UNIX workstations running IRAF. In particular, Cambridge is
    line_3:        a collaborator in the HST Medium Deep Survey Key Project for which dedicated
    line_4:        reduction facilities have been provided. Additional resources for this
    line_5:        collaboration have been provided by the European Economic Community.
    line_6:        This will pay for postdoctoral assistants, computing costs and associated
    line_7:        travel.

!
!end of general form text

general_form_address:

  lname:           Fort
    fname:         Bernard
    category:      PI
    inst:          5474
    addr_1:        Observatoire Midi-Pyrenees
    addr_2:        14, Avenue Edouard Belin
    city:          TOULOUSE
    zip:           31400
    country:       FRANCE
    phone:         011-33-61-332-821
    telex:         fort@obs-mip.fr

!

  lname:
    category:      CON

!
! end of general_form_address records

fixed_targets:

    targnum:       1
    name_1:        CL2244-02
    descr_1:       F,
    descr_2:       411,
    descr_3:       409
    pos_1:         RA= 22H 44M 38.3S +/- 0.1S,
    pos_2:         DEC= -02D 21' 30" +/- 1.0"
    equinox:       1950.0
    pos_epoch_yr:  1950.00
    rv_or_z:       Z = 0.329
    fluxnum_1:     1
    fluxval_1:     SURF(B)=24.5 +/- 0.5
    fluxnum_2:     2
    fluxval_2:     B-V = 0.2
    fluxnum_3:     3
    fluxval_3:     B-R = 0.9

!

    targnum:       2
    name_1:        ABELL2390
    descr_1:       F,
    descr_2:       411,
    descr_3:       404
    pos_1:         RA= 21H 51M 14.3S +/- 0.1S,
    pos_2:         DEC= +17D 27' 34.9" +/- 2.0"
    equinox:       1950.0
    pos_epoch_yr:  1950.00
    rv_or_z:       Z = 0.231
    fluxnum_1:     1
    fluxval_1:     SURF(B)=25.3 +/- 0.5
    fluxnum_2:     2
    fluxval_2:     B-R = 1.9

!
! end of fixed targets

! No solar system records found

! No generic target records found

exposure_logsheet:

    linenum:       1.000
    sequence_1:    DEFINE
    sequence_2:    SEQ1
    targname:      #
    config:        WFPC2
    opmode:        IMAGE
    aperture:      #
    sp_element:    F814W
    wavelength:    7940
    param_1:       CR-SPLIT=NO
    num_exp:       #
    time_per_exp:  2100S
    s_to_n:        3.5
    s_to_n_time:   11500S
    fluxnum_1:     1
    fluxnum_2:     2
    priority:      #
    req_1:         CYCLE 4;

!

    linenum:       2.000
    sequence_1:    DEFINE
    sequence_2:    SEQ2
    targname:      #
    config:        WFPC2
    opmode:        IMAGE
    aperture:      #
    sp_element:    F555W
    wavelength:    5407
    param_1:       CR-SPLIT=NO
    num_exp:       #
    time_per_exp:  2100S
    s_to_n:        3.5
    s_to_n_time:   6900S
    fluxnum_1:     1
    fluxnum_2:     2
    priority:      #
    req_1:         CYCLE 4;

!

    linenum:       3.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +5.0,-5.0

!

    linenum:       4.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +6.0,-4.0

!

    linenum:       5.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +7.0,-6.0;

!

    linenum:       6.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +4.0,-5.5

!

    linenum:       7.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +5.5,-6.5

!

    linenum:       8.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +3.5,-3.5

!

    linenum:       9.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +5.0,-5.0

!

    linenum:       10.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +6.0,-4.0

!

    linenum:       11.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +7.0,-6.0

!

    linenum:       12.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      CL2244-02
    aperture:      WF3
    num_exp:       1
    priority:      1
    req_1:         ORIENT 240D +/- 10D;
    req_2:         POS TARG +5.0,-5.5

!

    linenum:       13.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +10.3,-20.5

!

    linenum:       14.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +11.3,-19.5

!

    linenum:       15.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +12.3,-21.5

!

    linenum:       16.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +9.3,-21.0

!

    linenum:       17.000
    sequence_1:    USE
    sequence_2:    SEQ1
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +10.8,-22.0

!

    linenum:       18.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +10.3,-20.5

!

    linenum:       19.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +11.3,-19.5

!

    linenum:       20.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +12.3,-21.5

!

    linenum:       21.000
    sequence_1:    USE
    sequence_2:    SEQ2
    targname:      ABELL2390
    aperture:      WF2
    num_exp:       1
    priority:      1
    req_1:         ORIENT 85D +/- 20D;
    req_2:         POS TARG +9.3,-21.0

!
! end of exposure logsheet

! No scan data records found