Assigned ID: 452 ----- Submission 1 (Fri Jan 21 22:19:33 GMT 2005) ----- We propose a homogeneous analysis of all HST spectra of quasars and AGN that probe the low redshift intergalactic medium (z < 0.4). Data taken at moderate resolution with each of the three spectroscopic instruments -- FOS, GHRS, and STIS -- will be included. The analysis will involve 316 targets, span a total redshift path of ~110 and yield an estimated 1500 Lyman-alpha absorbers. In this redshift range, it will incease the number of absorbers by a factor of 15 over the HST Absorption Line Key Project. Data products include co-added and calibrated spectra, continuum fits, absorption line lists, and line identifications, all on a web site that includes hyperlinked information from NED and ADS. About 90% of the sightlines are in regions covered by the SDSS, 2dF and 6dF surveys. This Archive Legacy database will facilitate a range of scientific investigations, including (a) studies of the relationship between luminous baryons in galaxies and diffuse baryons in the IGM, (b) comparisons between the observations and simulations that incorporate gas dynamics, (c) measures of cosmic variance in structure on the largest scales, (d) new tests of the gravitational instability paradigm, (e) accurate determination of the proximity effect at low redshift, and (f) measurements of the chemical enrichment of the IGM. With no prospect of sensitive UV spectroscopy in the forseeable future, this dataset will form part of HST's unique and enduring legacy.

QUASAR ABSORPTION LINES AND IGM 12 253000. Budget split over 2 years. false 0.0 false false true false false SUPPORTED