6612( 8) - 03/15/96 12:04 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6612 Version: 8 Check-in Date: 15-Mar-1996 11:58:51 1.Proposal Title: Damped Lyman-alpha Absorption Lines from Moderate-Redshift Galaxies ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle QSO Absorption Lines GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Kenneth M. Lanzetta State University of New York at Stony Brook CoI: Arthur M. Wolfe University of California, San Diego N ------------------------------------------------------------------------------------ 6. Abstract We propose to obtain intermediate-resolution spectroscopy of eight moderate-redshift (0.05 < z < 0.8) candidate damped Ly- alpha\ absorption features that were detected toward higher- redshift background QSOs in an exhaustive search of the HST archival data base. This search forms a systematic, unbiased survey for moderate-redshift damped Ly-alpha\ absorbers. Accurate spectra of the candidate features will allow us to confirm (or otherwise) the damped nature of the absorption profiles and to determine the neutral hydrogen column densities. By combining the results of this ultraviolet survey with those derived from existing optical surveys we will determine the redshift evolution of the rate of incidence, cosmological mass density, and column density distribution of damped Ly-alpha\ absorbers over a redshift baseline spanning 0.05 < z < 4.0. We will furthermore secure a sample of moderate-redshift damped Ly-alpha\ absorbers for further detailed study. These results will constrain theories of galaxy formation and evolution and will help to determine the type or types of galaxies responsible for the absorption. ------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 2] Observations Description ------------------------ We require observations of eight candidate damped LyAlpha absorption features toward six background QSOs in order to generate a statistically complete sample of absorption systems. Based on our experience with similar spectra obtained at optical wavelengths and on simulations of the planned HST observations, we estimate that in order to unambiguously confirm (or otherwise) the damped nature of the candidate damped LyAlpha absorption features and to determine accurate neutral hydrogen column densities we require signal- to-noise ratios (in the continuum) of S/N ~ 15 per diode with the GHRS and grating G140L or the FOS and grating G190H. To estimate the exposure times required to obtain these signal-to-noise ratios, we determined actual ultraviolet fluxes from the HST spectra and used the sensitivity curves and aperture throughputs quoted in the Faint Object Spectrograph Instrument Handbook, Version 6.0 and the Instrument Handbook for the Goddard High Resolution Spectrograph (GHRS), Version 6.0. At the wavelengths of interest, ultraviolet fluxes of the background QSOs in our sample range from 0.15 * 10^-14 through 1.0 * 10^-14 erg s^-1 cm^-2 AA^-1, with 0.3 * 10^-14 erg s^-1 cm^-2 AA^-1 being typical. As an example, consider an object observed at Lambda = 1850 Angstrom\\ with f_Lambda = 0.3 * 10^-14 erg s^ -1 cm^-2 AA^-1 using the FOS with G190H and the red detector. From Table 1--7 of the Faint Object Spectrograph Instrument Handbook, the count rate is found to be 0.2 count s^-1 diode^ -1. This count rate greatly exceeds the dark count rate of 0.01 count s^-1 diode^-1, and the background is negligible, so dark and background counts may be neglected. A total of 225 counts per diode (i.e. a signal-to-noise ratio of S/N = 15 per diode) may therefore be obtained in an exposure time of 1125 s. We will adopt FOS-assisted target acquisition for the GHRS exposures and PEAKUP target acquisition for the FOS exposures. In most cases we can easily fit the guide star acquisition, the target acquisition, and the science exposure into two orbits, although in one case we require one orbit and in one case we require three orbits. (We will pad, or in a few cases trim, exposure times as necessary to fill orbits.) Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Kenneth M. Lanzetta*Department of Earth and Space Sciences*State University of New York at Stony Brook*Stony Brook, NY 11794-2100 Ship Via: UPS Email: lanzetta@sbastc.ess.sunysb.edu , ------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 UM301 GALAXY,QSO RA = 01H 03M 12.960S +/- 0.07S, 2000 Z=0.39 V = 17.7+/-0.5 DEC = +02D 21' 10.70" +/- 0.1", PLATE-ID=04YD 2 3C95 GALAXY,QSO RA = 03H 51M 28.55S +/- 0.07S, 2000 Z=0.616 V = 16.22+/-0.5 DEC = -14D 29' 09.0" +/- 0.1", B-V = 0.33+/-0.1 PLATE-ID=029R U-B = -0.56+/-0.1 3 US1867 GALAXY,QSO RA = 08H 53M 34.20S +/- 0.07S, 2000 Z=0.513 V = 16.4+/-0.5 DEC = +43D 49' 0.20" +/- 0.1", PLATE-ID=00XV 4 PG1338+416 GALAXY,QSO RA = 13H 41M 0.770S +/- 0.07S, 2000 Z=1.219 V = 16.08+/-0.5 DEC = +41D 23' 13.50" +/- 0.1", PLATE-ID=00XY 5 PG1352+011 GALAXY,QSO RA = 13H 54M 58.670S +/- 0.07S, 2000 Z=1.121 V = 16.03+/-0.5 DEC = +00D 52' 10.10" +/- 0.1", PLATE-ID=014F 6 4C11.72 GALAXY,QSO RA = 22H 54M 10.43S +/- 0.07S, 2000 Z=0.323 V = 15.77+/-0.5 DEC = +11D 36' 39.00" +/- 0.1", B-V = 0.17+/-0.1 PLATE-ID=00JD U-B = -0.87+/-0.1 6612( 8) - 03/15/96 12:04 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 UM301 FOS/BL ACQ/PEA 4.3 MIRROR SCAN-STEP- 1 2.34S ONBOARD ACQUISITION FOR 2 K Y=1.204,SEARCH- SIZE-X=1,SEARCH -SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 2 UM301 FOS/BL ACQ/PEA 1.0 MIRROR SCAN-STEP- 1 2.34S ONBOARD ACQUISITION FOR 3 K X=0.602,SCAN- STEP- Y=0.602,SEARCH- SIZE-X=6,SEARCH Comments: -SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 3 UM301 FOS/BL ACQ/PEA 0.5 MIRROR SCAN-STEP- 1 2.34S ONBOARD ACQUISITION FOR 4 K X=0.29,SCAN- STEP- Y=0.29,SEARCH- SIZE-X=3,SEARCH Comments: -SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 4 UM301 FOS/BL ACQ/PEA 0.3 MIRROR SCAN-STEP- 1 10S ONBOARD ACQUISITION FOR 5-7 K X=0.172,SCAN- STEP- Y=0.172,SEARCH- SIZE-X=3,SEARCH Comments: -SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 5 UM301 FOS/BL ACCUM 1.0 G190H 1628.8 1 180.0S MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ 6 UM301 FOS/BL ACCUM 1.0 G190H 1628.8 1 2400.0S MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ 7 UM301 FOS/BL ACCUM 1.0 G190H 1628.8 1 2401.0S MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 5] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 3C95 FOS/BL ACQ/BIN 4.3 MIRROR 1 8.9S ONBOARD ACQUISITION FOR 2 ARY ------------------------------------------------------------------------------------------------------------------------------------ 2 3C95 HRS ACCUM 2.0 G140L 1303.8 STEP- 15 299.2S PATT=DEF,FP- SPLIT=NO,COMB=F OUR ------------------------------------------------------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 6] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 US1867 FOS/BL ACQ/BIN 4.3 MIRROR 1 13.1S ONBOARD ACQUISITION FOR 2 ARY ------------------------------------------------------------------------------------------------------------------------------------ 2 US1867 HRS ACCUM 2.0 G140L 1409.7 STEP- 16 299.2S PATT=DEF,FP- SPLIT=NO,COMB=F OUR ------------------------------------------------------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 7] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG1338+416 FOS/RD ACQ/BIN 4.3 MIRROR 1 3.4S ONBOARD ACQUISITION FOR 2 ARY ------------------------------------------------------------------------------------------------------------------------------------ 2 PG1338+416 FOS/RD ACCUM 1.0 G190H 1945.0 1 1690.0S MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ 3 PG1338+416 FOS/RD ACCUM 1.0 G190H 1945.0 1 2500.0S MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 8] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PG1352+011 FOS/RD ACQ/BIN 4.3 MIRROR 1 3.3S ONBOARD ACQUISITION FOR 2 ARY ------------------------------------------------------------------------------------------------------------------------------------ 2 PG1352+011 FOS/RD ACCUM 1.0 G190H 1852.3 1 1580.0S MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 9] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 4C11.72 FOS/BL ACQ/PEA 4.3 MIRROR SCAN-STEP- 1 1S ONBOARD ACQUISITION FOR 2 K Y=1.204,SEARCH- SIZE-X=1,SEARCH -SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 2 4C11.72 FOS/BL ACQ/PEA 1.0 MIRROR SCAN-STEP- 1 1S ONBOARD ACQUISITION FOR 3 K X=0.602,SCAN- STEP- Y=0.602,SEARCH- SIZE-X=6,SEARCH Comments: -SIZE-Y=2 ------------------------------------------------------------------------------------------------------------------------------------ 3 4C11.72 FOS/BL ACQ/PEA 0.5 MIRROR SCAN-STEP- 1 10S ONBOARD ACQUISITION FOR 4 K X=0.29,SCAN- STEP- Y=0.29,SEARCH- SIZE-X=3,SEARCH Comments: -SIZE-Y=3 ------------------------------------------------------------------------------------------------------------------------------------ 4 4C11.72 HRS ACCUM 2.0 G140L 1313.0 10 299.2S ------------------------------------------------------------------------------------------------------------------------------------ 6612( 8) - 03/15/96 12:04 - [ 10] Summary Form for Proposal 6612 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL HRS FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ACQ/BINARY ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=1.204 SEARCH-SIZE-X=1 SEARCH-SIZE-Y=3 SEARCH-SIZE-Y=2 SEARCH-SIZE-X=3 SCAN-STEP-Y=0.172 COMB=FOUR FP-SPLIT=NO SEARCH-SIZE-X=6 SCAN-STEP-Y=0.29 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category QSO Absorption Lines ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQUISITION FOR 2 ONBOARD ACQUISITION FOR 3 ONBOARD ACQUISITION FOR 4 ONBOARD ACQUISITION FOR 5-7 MIN DUR 80%; MAX DUR 1000% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G190H G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names UM301 3C95 US1867 PG1338+416 PG1352+011 4C11.72 ------------------------------------------------------------------------------------------------------------------------------------