CTIO  > Science Talks  >  Abstracts

Brian Keeney
University of Colorado
& NOAO South Visiting Astronomer
 

"Probing Galaxies Through Quasar Absorption Lines with HST/COS"
 

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.