The Gaseous Environments of High-Redshift Galaxies:
The CGM and ISM of Star-Forming Systems 2<z<3

Gwen Rudie
(Carnegie-Princeton Fellow)

The gaseous component of galaxies is a crucial but poorly-constrained
aspect of galaxy formation and evolution. I will present results from
the Keck Baryonic Structure Survey (KBSS), a unique spectroscopic
survey designed to explore both the physical properties of
high-redshift galaxies and the connection between these galaxies and
their surrounding intergalactic baryons. The KBSS is optimized to
trace the cosmic peak of star formation (z~2-3), combining Keck/HIRES
spectra of 15 hyperluminous QSOs with densely-sampled galaxy redshift
surveys surrounding each QSO sightline. I will characterize the
physical properties of the CGM gas through the spatial distribution,
column densities, kinematics, and absorber line widths of ~6000 HI
absorbers surrounding ~900 foreground star-forming galaxies within 50
kpc to 3 Mpc of a sightline.  These measurements provide clear
evidence of gas inflow and outflow as well as accretion shocks or hot
outflows from these forming galaxies. I will compare these
observations with recent theoretical predictions, highlighting
discrepancies that suggest our theoretical picture of gas flows into
and out of galaxies is still incomplete. I will also discuss
KBSS-MOSFIRE, a rest-frame optical spectroscopic survey of galaxies in
these same QSO fields. These data provide new insight into the
physical properties of HII regions within these star-forming systems.