!   $Id: 5631,v 2.1 1994/07/27 19:55:35 pepsa Exp $
coverpage:
  title_1:         A NEW SIZE CONSTRAINT ON LYMAN ALPHA CLOUDS: HOPR #202
    sci_cat:       QUASARS AND AGN
    sci_subcat:    QUASAR ABSORPTION
    proposal_for:  GO
cont_id: 5320
    pi_fname:      CRAIG
    pi_mi:         B.
    pi_lname:      FOLTZ
    pi_inst:       MULTIPLE MIRROR TELESCOPE
    pi_country:    USA
    pi_phone:      602-621-1269
    hours_pri:     16.96
    num_pri:       6
    fos:           Y
    off_fname:     MICHAEL
    off_lname:     CUSANOVICH
    off_title:     V.P. FOR RESEARCH
    off_inst:      UNIVERSITY OF ARIZONA
    off_addr_1:    ADMINISTRATION BLDG 601
    off_addr_2:    UNIVERSITY OF ARIZONA
    off_city:      TUCSON
    off_state:     AZ
    off_zip:       85721
    off_country:   USA
    off_phone:     602-621-3513
abstract:
    line_1:        Although they have been the target of extensive ground- and space-based
    line_2:        investigations as well as intense theoretical modelling, the physical nature
    line_3:        of the absorbing clouds responsible for the Lyman alpha forest of absorption
    line_4:        seen shortward of 1215 A in the rest frame of all QSOs remains elusive. Optical
    line_5:        and UV data have yielded column density, Doppler parameter, and redshift
    line_6:        distributions, but the determination of gas density and ionization fractions
    line_7:        requires a knowledge of the size of the absorber.  Ground-based constraints
    line_8:        derived from observations of gravitationally-lensed and projected pairs of
    line_9:        QSOs allow for a wide range of sizes:  10 kpc < r < 1 Mpc.  We propose to
    line_10:       observe three relatively bright, intermediate-redshift pairs of QSOs, with
    line_11:       separations on the sky of roughly an arcminute to search for common Lyman alpha
    line_12:       forest lines in the redshift range from 0.35 to 1.7.  Numerical simulations
    line_13:       show that these observations will be sensitive to cloud sizes greater than
    line_14:       about 100 kpc.  If the characteristic size of the clouds is in the range from
    line_15:       100 kpc to 1 Mpc an estimate of the size will result from the fraction of
    line_16:       absorption lines common along two nearby lines of sight.  In the case of no
    line_17:       common features, the upper limit on the size of the clouds will be reduced by
    line_18:       more than a factor of 4.
line_20:  This is a HOPR (#202) REPEAT FOR for PKS0254-344,Q0254-344,LB9605(V1) only.
general_form_proposers:
  lname:           FOLTZ
    fname:         CRAIG
    mi:            B.
    inst:          1216
    country:       USA
  lname:           IMPEY
    fname:         CHRIS
    mi:            D.
    inst:          1212
    country:       USA
  lname:           DINSHAW
    fname:         NADINE
    inst:          1212
    country:       USA
general_form_text:
  question:        3
    section:       1
    line_1:        Three pairs of quasars will be observed with the red side of the FOS. The
    line_2:        G190H and G270H gratings will give spectral coverage from 1650-3280 A,
    line_3:        corresponding to 0.35 < z < 1.7 for Lyman-alpha absorbers.  The two high
    line_4:        redshift pairs will be observed with both the G190H and G270H gratings, and
    line_5:        the lower redshift pair with just the G190H grating. All three targets can
    line_6:        be acquired in ACQ/BINARY mode with the large 4.3 arcsecond aperture and
    line_7:        the observations will be made in the 0.9 arcsecond circular aperture. One
    line_8:        internal wavelength calibration frame will be acquired at both gratings for
    line_9:        the high-z quasars and at only the G190H grating for the lower-z quasars.
    line_11:       The integration times are scaled to yield a SNR per diode of about 50 which
    line_12:       gives a better than 5 sigma equivalent width limit for unresolved absorption
    line_13:       lines of 0.3 A at 2300 A for the G190H observations and at 2650 A for G270H.
    line_14:       A 0.3 A equivalent width line will be detected at greater than 3 sigma
    line_15:       everywhere in the G270H spectra and longward of 1650 A in the G190H spectra.
    line_16:       Shortward of 1650 A in the G190H spectra, such a line will fall below 3-sigma
    line_17:       significance. The quoted SNRs are estimated from the observed V magnitudes by
    line_18:       assuming a power law slope of nu^-1.
line_20: This is a HOPR (#202) repeat for PKS0254-344,Q0254-344,LB9605(VISIT1) only.
  question:        4
    section:       1
    line_1:        This observation requires the ultraviolet spectroscopic capability of
    line_2:        the HST.  Ground-based observations of Lyman-alpha absoprtion lines are
    line_3:        only possible for redshifts above z = 1.7. Since the quasars have
    line_4:        redshifts up to z = 2, we plan ground-based spectroscopy using the
    line_5:        Multiple Mirror Telescope to augment the HST data (the ground-based
    line_6:        data will also be essential in weeding out metal lines from the
    line_7:        relatively small number of Lyman-alpha lines).  However, most of the
    line_8:        path length to absorption, and most of the expected absorbers, are at
    line_9:        wavelengths below 3200 Angstroms that can only be studied by HST. Also,
    line_10:       it is by no means clear that the high and low redshift Lyman-alpha
    line_11:       absorbers represent the same kind of object.  There is some indication
    line_12:       that the slope of dN/dz flattens below z = 1.5.  Therefore a new
    line_13:       constraint on the sizes of low redshift Lyman-alpha clouds is desirable
    line_14:       independent of ground-based data. We also note that this observation is
    line_15:       complementary to the scientific goals of the Quasars Key Project. The
    line_16:       Key Project will eventually have enough absorbers to calculate whether
    line_17:       Lyman-alpha clouds cluster in the same way as galaxies at low redshift.
    line_18:       The use of pairs, however, gives size information that cannot be
    line_19:       obtained either from a 2-point correlation function or from an
    line_20:       autocorrelation function along a single line of sight.
  question:        6
    section:       1
    line_1:        The success of this proposal relies on whether the absorption features of
    line_2:        one quasar can be unambiguously identified as being common (or not) to
    line_3:        those of the other quasar in a pair. This demands accurate calibration of
    line_4:        the zero point of the wavelength scale within a pair. According to Papers I
    line_5:        and II of the HST Quasar Absorption Line Key Project, the rms scatter in
    line_6:        the zero point is about 0.5 A in the G190H and G270H gratings.  The offsets
    line_7:        can be determined from the Galactic absorption lines, however in calibrating
    line_8:        the G190H spectra only the Al II 1670 line is suitable and is not always well
    line_9:        detected (Paper II, preprint, p9).  Therefore one wavelength calibration
    line_10:       frame following an exposure at each grating for each of the quasars is
    line_11:       required. We will not need a calibration frame for every exposure because
    line_12:       the relative zero-point shifts between exposures of a given quasar can be
    line_13:       calculated by cross-correlating the individual exposures of that quasar.
  question:        9
    section:       1
    line_1:        Previous HST observing time awarded us is as follows:
    line_2:        GO Program 2524 "Spectropolarimetry of Bright Quasars" - IMPEY
    line_3:        GO Program 3732 "Spectropolarimetry of Bright Quasars" - IMPEY
    line_4:        GO Program 3648 "Imaging of BL Lac Host Galaxies and Environments" - IMPEY
    line_5:        GO Program 4402 "A Study of the Gravitational Lens 1422+321" - IMPEY, FOLTZ
    line_6:        Papers on the results of GO Programs 2524 and 3732 are in preparation. The data
    line_7:        from GO Program 3648 have been received and are being reduced. The observations
    line_8:        for GO Program 4402 have not yet been made.
  question:        10
    section:       1
    line_1:        The University of Arizona will provide central computing services (hard disks,
    line_2:        networks, tape drives) in support of this project. One undergraduate will be
    line_3:        able to work on this project.  We will also be supported by the University of
    line_4:        Arizona and the Smithsonian Institution in follow-up ground-based spectroscopy
    line_5:        spectroscopy of the quasar pairs using the Multiple Mirror Telescope.
general_form_address:
  lname:           FOLTZ
    fname:         CRAIG
    mi:            B.
    category:      PI
    inst:          1216
    addr_1:        MMT OBSERVATORY
    addr_2:        UNIVERSITY OF ARIZONA
    city:          TUCSON
    state:         AZ
    zip:           85721
    country:       USA
    phone:         602-621-1269
    telex:         602-670-5740
  lname:
    category:      CON
fixed_targets:
    targnum:       1
    name_1:        PKS0254-334
    name_2:        Q0254-334A
    descr_1:       E,313
    pos_1:         PLATE-ID = 02IV,
    pos_2:         RA = 02H 56M 42.60S +/- 1.0",
    pos_3:         DEC = -33D 15' 22.6" +/- 1.0"
    equinox:       J2000.0
    rv_or_z:       Z=1.915
    comment_1:     COMPONENT A OF
    comment_2:     QUASAR PAIR Q0254-334A AND B
    fluxnum_1:     1
    fluxval_1:     V=17.0
    targnum:       2
    name_1:        Q0254-334
    name_2:        Q0254-334B
    descr_1:       E,313
    pos_1:         PLATE-ID = 02IV,
    pos_2:         RA = 02H 56M 47.85S +/- 1.0",
    pos_3:         DEC = -33D 15' 26.3" +/- 1.0"
    equinox:       J2000.0
    rv_or_z:       Z=1.863
    comment_1:     COMPONENT B OF
    comment_2:     QUASAR PAIR Q0254-334A AND B
    fluxnum_1:     1
    fluxval_1:     V=16.5
    targnum:       5
    name_1:        LB9605
    descr_1:       E,313
    pos_1:         PLATE-ID = 027J,
    pos_2:         RA = 15H 19M 13.41S +/- 1.0",
    pos_3:         DEC = +23D 46' 57.4" +/- 1.0"
    equinox:       J2000.0
    rv_or_z:       Z=1.834
    fluxnum_1:     1
    fluxval_1:     V=18.4
exposure_logsheet:
    linenum:       1.000
    targname:      PKS0254-334
    config:        FOS/RD
    opmode:        ACQ/BINARY
    aperture:      4.3
    sp_element:    MIRROR
    num_exp:       1
    time_per_exp:  13.9S
    s_to_n:        20
    fluxnum_1:     1
    priority:      1
    req_1:         CYCLE 4 / 1-7 ; ONBOARD ACQ FOR 2-7
    linenum:       2.000
    targname:      PKS0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  35M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       3.000
    targname:      PKS0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  35M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       4.000
    targname:      WAVE
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  DEF
    priority:      1
    req_1:         CALIB FOR 3 NO SLEW ; GROUP 3-4 NO GAP
    comment_1:     DO NOT CHANGE GRATING POSITION BETWEEN
    comment_2:     EXPOSURES 3 AND 4
    linenum:       5.000
    targname:      PKS0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G270H
    wavelength:    2223-3278
    num_exp:       1
    time_per_exp:  24M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       6.000
    targname:      PKS0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G270H
    wavelength:    2223-3278
    num_exp:       1
    time_per_exp:  24M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       7.000
    targname:      WAVE
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G270H
    wavelength:    2223-3278
    num_exp:       1
    time_per_exp:  DEF
    priority:      1
    req_1:         CALIB FOR 6 NO SLEW ; GROUP 6-7 NO GAP
    comment_1:     DO NOT CHANGE GRATING POSITION BETWEEN
    comment_2:     EXPOSURES 6 AND 7
    linenum:       8.000
    targname:      Q0254-334
    config:        FOS/RD
    opmode:        ACQ/BINARY
    aperture:      4.3
    sp_element:    MIRROR
    num_exp:       1
    time_per_exp:  8.8S
    s_to_n:        20
    fluxnum_1:     1
    priority:      1
    req_1:         CYCLE 4 / 8-13 ; ONBOARD ACQ FOR 9-13
    linenum:       9.000
    targname:      Q0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  23M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       10.000
    targname:      Q0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  23M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       11.000
    targname:      WAVE
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  DEF
    priority:      1
    req_1:         CALIB FOR 10 NO SLEW ; GROUP 10-11 NO GAP
    comment_1:     DO NOT CHANGE GRATING POSITION BETWEEN
    comment_2:     EXPOSURES 10 AND 11
    linenum:       12.000
    targname:      Q0254-334
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G270H
    wavelength:    2223-3278
    num_exp:       1
    time_per_exp:  28M
    s_to_n:        50
    fluxnum_1:     1
    priority:      1
    linenum:       13.000
    targname:      WAVE
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G270H
    wavelength:    2223-3278
    num_exp:       1
    time_per_exp:  DEF
    priority:      1
    req_1:         CALIB FOR 12 NO SLEW ; GROUP 12-13 NO GAP
    comment_1:     DO NOT CHANGE GRATING POSITION BETWEEN
    comment_2:     EXPOSURES 12 AND 13
    linenum:       35.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACQ/BINARY
    aperture:      4.3
    sp_element:    MIRROR
    num_exp:       1
    time_per_exp:  50.3S
    s_to_n:        20
    fluxnum_1:     1
    priority:      1
    req_1:         CYCLE 4 / 35-42 ; ONBOARD ACQ FOR 36-42
    linenum:       36.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  37M
    s_to_n:        45
    fluxnum_1:     1
    priority:      1
    linenum:       37.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  37M
    s_to_n:        45
    fluxnum_1:     1
    priority:      1
    linenum:       38.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  37M
    s_to_n:        45
    fluxnum_1:     1
    priority:      1
    linenum:       39.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  37M
    s_to_n:        45
    fluxnum_1:     1
    priority:      1
    linenum:       40.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  37M
    s_to_n:        45
    fluxnum_1:     1
    priority:      1
    linenum:       41.000
    targname:      LB9605
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  37M
    s_to_n:        45
    fluxnum_1:     1
    priority:      1
    linenum:       42.000
    targname:      WAVE
    config:        FOS/RD
    opmode:        ACCUM
    aperture:      1.0
    sp_element:    G190H
    wavelength:    1565-2312
    num_exp:       1
    time_per_exp:  DEF
    priority:      1
    req_1:         CALIB FOR 41 NO SLEW ; GROUP 41-42 NO GAP
    comment_1:     DO NOT CHANGE GRATING POSITION BETWEEN
    comment_2:     EXPOSURES 41 AND 42
!~~~RPSS~~~,PSTANLEY,5320new.hopr, 8-MAR-1994 14:56