Assigned ID: 799 ----- Attempting Submission 1 (Fri Feb 25 23:47:58 GMT 2011) ----- HST Phase I Proposal 799 (archival.apt) successfully submitted. ----- Attempting Submission 2 (Sat Feb 26 21:15:20 GMT 2011) ----- We will carry out a survey for damped Lya systems (DLAs) at z<1 with the STIS, FOS, and COS spectroscopic archive of HST. Previously Rao and Turnshek found 41 z~1 DLAs with HST through the pre-selection of systems with strong MgII absorption. These efforts provide the basis for our current knowledge on the distribution and mass of HI gas in galaxies over the past ~10Gyr. However, MgII pre-selection may suffer from systematic bias. Furthermore, the technique has been primarily limited to z>0.6 and results related to redshift evolution are sensitive to the assumed mapping of MgII to DLAs. With the installment of COS on HST, we shall perform a a survey without pre-selection for DLAs at z<1. This can be performed with the existing dataset of UV spectroscopy. With the proposed funding, our group will establish the observational criteria for such analysis, develop custom software for DLA fitting in the Poisson-limited regime of COS, and perform the first comprehensive, unbiassed survey of DLAs at z<1. We will disseminate our results through publications and with a dedicated website that will be updated to include new observations. We predict the detection of 15-40 new DLAs. Analysis of these systems will constrain the HI frequency distribution for galaxies over the past ~10Gyr and provide a new estimate of the cosmological mass density of neutral gas. Furthermore, the COS data (especially) will yield a sample of 10+ DLAs at z<0.1 for unique, high-fidelity follow-up observations in UV-IR passbands, and 21cm wavelengths. These DLAs will also be used for calibration of the CII* technique for inferring star formation rates in high-z DLAs.

QUASAR ABSORPTION LINES AND IGM 12 Medium false 0.0 0.0 false false false false SUPPORTED