Metal-line system survey: characterizing the low-redshift IGM

Abstract

The low-redshift IGM probes the last ten billion years of metal enrichment from galactic feedback processes. We present preliminary results from a survey of intergalactic metal-line absorption systems in archival HST STIS, GHRS, and FUSE spectra of ≈50 z≲2 UV-bright objects. We summarize the detailed analysis of one sightline (PKS1302–102, z_QSO=0.2784) with which we set the methodology for the larger survey. We use simple CLOUDY models to constrain the ionizing mechanism(s) and metallicities for the metal-line systems. For about 15 sightlines, including PKS1302–102, we have a complementary galaxy survey, and we look for correlations between galaxies and absorption systems in order to understand the large-scale distribution of the metal-enriched IGM.