Probing Galaxies Through Quasar Absorption Lines with HST/COS (Brian Keeney, Center for Astrophysics and Space Astronomy, Colorado)

The intergalactic medium (IGM) is filled with hydrogen and metal lines

as far into the early Universe as we are able to probe with quasar

absorption line systems.  Metal line absorbers presumably originated

in a star forming galaxy, making the association of galaxies and

quasar absorption line systems an interesting test and our best

current probe of galactic infall/outflow models.  However, while the

absorption-line statistics are best at high redshift it is only at the

lowest redshifts that we can probe the faint end of the galaxy

luminosity function to determine the contribution of dwarf galaxies to

IGM enrichment.  

With 20-30 times the throughput of the Hubble Space Telescope's

previous far-UV spectrographs at comparable resolution, the

recently-installed Cosmic Origins Spectrograph (COS) is

revolutionizing studies of the low-redshift IGM.  I will present

results from recent studies of low-redshift galaxy/absorber

associations and discuss the progress of ongoing galaxy redshift

surveys around COS sight lines being performed with the HYDRA

spectrographs of NOAO.