12308( 2) - 12-Jul-2010 12:14:47 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12308 Version: 2 Check-in Time: 12-Jul-2010 12:14:47 STScI Edit Number: 0 Title Cosmic Metallicity from ZnII-Selected QSO Absorption Line Systems Near Redshift z=1.2 ------------------------------------------------------------------------------------ Type Cycle GO 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Eric M. Monier State University of New York College at Brockport CoI: Dr. David A. Turnshek University of Pittsburgh N CoI: Dr. Sandhya M. Rao University of Pittsburgh N ------------------------------------------------------------------------------------ Abstract We have searched nearly 15, 000 strong intervening MgII systems in SDSS quasar spectra to measure spectral regions where weak, unsaturated metal lines are predicted to exist, with the aim of finding a representative sample of the strongest metal-line column density systems in the universe. These systems are clearly damped Lyman-alpha (DLA) systems, which track cosmologically intervening neutral gas regions that fall along the sightlines to background quasars. We propose STIS G230L spectroscopy of seven strong-ZnII-selected systems from this sample in order to measure their Lyman-alpha absorption profiles and derive their HI column densities. Since Zn is not depleted onto grains, measurement of N(HI) allows a direct measurement of the metal abundance in such systems. We expect the results to be representative of the upper envelope of the distribution of neutral-gas-phase metallicities near redshift z=1.2. If these systems are high-N(HI) DLAs (e.g., 6E21 atoms/cm^2) they will have metallicities typical of those normally found in DLAs (e.g., one-tenth solar). However, if they are low-N(HI) DLAs (e.g., 2E20 atoms/cm$^2$), they will have supersolar metallicities. Since these DLAs are selected on the basis of their extreme metal-line properties, analysis of their metallicities and dust-to-gas ratios will lead to strong constraints on the range of properties exhibited by DLA systems. ------------------------------------------------------------------------------------ Observations Description ------------------------ All eight of our targets are QSOs with intervening absorption systems at z~1.2, and all have large Zn+ absorption column densities. All of the targets have Sloan (u, g, r, i, z) fluxes measured to within several percent; four of the eight targets also have GALEX NUV magnitudes available. On an f(lambda) scale, all of the SDSS spectra are seen to rise into the UV. The z_em and z_abs of the targets were selected such that there is no possibility that Lyman limit absorption near z_em can block observation of Ly-alpha at z_abs. We propose to observe the corresponding Ly-alpha absorption line in each system to measure their neutral column densities and thereby derive their metal abundances. Based on the ZnII measurements, these are the best candidates for supersolar metallicity DLAs. Results on Cr, Fe, Mn, and Si are also available. All of the observations will be made with the STIS G230L grating. To 12308( 2) - 12-Jul-2010 12:14:47 - [ 2] extrapolate into the UV and calculate exposure times we used the exposure time calculator (ETC). Based on archival spectra, we estimate that S/N=8 per resolution element is adequate for our measurements. We used the QSOs' GALEX NUV magnitudes (or the SDSS g values when NUV magnitudes were unavailable) and the SDSS/FOS quasar templates of the ETC to predict the exposure time necessary to achieve S/N=8 per resolution element. The Ly-alpha lines are expected to be damped, and therefore they will have very large absorption equivalent widths, which can be very easily measured with this S/N at this resolution. Given this requirement, the ETC values imply that 1-2 orbits are required per object. For the four single-orbit observations the S/N ratios will be higher. All eight observations will be made in the 52 x 0.2 arc sec slit, and will be CR-SPLIT to eliminate cosmic rays. The resolution will be R~500 with 1.58 Ang/pix and S/N~8 per resolution element, which is sufficient for measuring the column densities of the broad damped Ly-alpha lines to within an accuracy of <30% based on Voigt profile fits. This is possible because the DLA lines are not only strong but also resolved at the resolution of the STIS G230L gration. The coordinates are from SDSS and are in the ICRS frame. T Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12308( 2) - 12-Jul-2010 12:14:47 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 0953+6351 GALAXY, QSO RA=09H53M24.5664S +/- 0.2", J2000 Z = V = 17.90 +/- .05 DEC=+63D51'3.17" +/- 0.2" 1.3103 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 2 0831+3635 GALAXY, QSO RA=08H31M57.7944S +/- 0.2", J2000 Z = V = 18.24 +/- .05 DEC=+36D35'53.05" +/- 0.2" 1.1598 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 3 1353+0333 GALAXY, QSO RA=13H53M9.4704S +/- 0.2", J2000 Z = V = 18.60 +/- .05 DEC=+03D33'28.04" +/- 0.2" 1.5873 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 4 SDSS-J025414 GALAXY, QSO RA=02H54M14.6184S +/- 0.2", J2000 Z = V = 17.71 +/- .05 .61-073435.4 DEC=-07D34'35.51" +/- 0.2" 1.4722 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 5 SDSS-J135535 GALAXY, QSO RA=13H55M35.8248S +/- 0.2", J2000 Z = V = 18.78 +/- .05 .81+004213.1 DEC=+00D42'13.07" +/- 0.2" 1.6206 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 6 SDSS-J120520 GALAXY, QSO RA=12H05M20.4672S +/- 0.2", J2000 Z = V = 18.41 +/- .05 .46+314433.6 DEC=+31D44'33.61" +/- 0.2" 1.6895 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 7 SDSS-J145300 GALAXY, QSO RA=14H53M0.5424S +/- 0.2", J2000 Z = V = 18.51 +/- .05 .55+313617.1 DEC=+31D36'17.10" +/- 0.2" 1.8118 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 8 SDSS-J120400 GALAXY, QSO RA=12H04M0.2808S +/- 0.2", J2000 Z = V = 18.38 +/- .05 .28+033849.8 DEC=+03D38'49.88" +/- 0.2" 1.5452 Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 12308( 2) - 12-Jul-2010 12:14:47 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 0953+6351 STIS/CCD ACQ F28X50LP MIRROR 1 7 S Comments: Onboard ACQ for 2 ------------------------------------------------------------------------------------------------------------------------------------ 2 0953+6351 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2400 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ 0953+6351 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 0953+6351 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2686.0 S -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 5] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 0831+3635 STIS/CCD ACQ F28X50LP MIRROR 1 9 S Comments: Onboard ACQ for 2 ------------------------------------------------------------------------------------------------------------------------------------ 2 0831+3635 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2400 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ 0831+3635 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 0831+3635 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2463.0 S -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 6] Visit: 03 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 1353+0333 STIS/CCD ACQ F28X50LP MIRROR 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 2 1353+0333 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2300 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ 3 1353+0333 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2700 S -MAMA see below ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ 1353+0333 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 1353+0333 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2392.0 S -MAMA 1353+0333 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2984.0 S -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 7] Visit: 04 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J02541 STIS/CCD ACQ F28X50LP MIRROR 1 6 S 4.61-073435 .4 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J02541 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2404 S 4.61-073435 -MAMA see below .4 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J025414.61-073 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 435.4 SDSS-J025414.61-073 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2416.0 S 435.4 -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 8] Visit: 05 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J13553 STIS/CCD ACQ F28X50LP MIRROR 1 12 S 5.81+004213 .1 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J13553 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2350 S 5.81+004213 -MAMA see below .1 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J13553 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2800 S 5.81+004213 -MAMA see below .1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J135535.81+004 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 213.1 SDSS-J135535.81+004 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2384.0 S 213.1 -MAMA SDSS-J135535.81+004 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2984.0 S 213.1 -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 9] Visit: 06 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J12052 STIS/CCD ACQ F28X50LP MIRROR 1 9 S 0.46+314433 .6 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J12052 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2400 S 0.46+314433 -MAMA see below .6 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J120520.46+314 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 433.6 SDSS-J120520.46+314 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2437.0 S 433.6 -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 10] Visit: 07 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J14530 STIS/CCD ACQ F28X50LP MIRROR 1 10 S 0.55+313617 .1 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J14530 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2000 S 0.55+313617 -MAMA see below .1 ------------------------------------------------------------------------------------------------------------------------------------ 3 SDSS-J14530 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2500 S 0.55+313617 -MAMA see below .1 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J145300.55+313 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 617.1 SDSS-J145300.55+313 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2433.0 S 617.1 -MAMA SDSS-J145300.55+313 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 3025.0 S 617.1 -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 11] Visit: 08 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SDSS-J12040 STIS/CCD ACQ F28X50LP MIRROR 1 9 S 0.28+033849 .8 ------------------------------------------------------------------------------------------------------------------------------------ 2 SDSS-J12040 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2350 S 0.28+033849 -MAMA see below .8 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SDSS-J120400.28+033 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 849.8 SDSS-J120400.28+033 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2396.0 S 849.8 -MAMA 12308( 2) - 12-Jul-2010 12:14:47 - [ 12] Summary Form for Proposal 12308 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G230L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names 0831+3635, 0953+6351, 1353+0333, SDSS-J025414.61-073435.4, SDSS-J120400.28+033849.8, SDSS-J120520.46+314433.6, SDSS-J135535.81+004213.1, SDSS-J145300.55+313617.1 ------------------------------------------------------------------------------------------------------------------------------------