|Speaker||Talk Date||Talk Series|
|Michael Shull (Colorado)||24 October 2013||Institute of Astronomy Colloquia|
I present a survey of ultraviolet spectroscopic observations with the Cosmic Origins Spectrograph on the Hubble Space Telescope. I will describe the current status of the local baryon census, observations and theoretical modeling of thermal phases of the intergalactic medium (IGM), and the extent of heavy element transport away from galaxies. Other new results include the COS composite spectrum of quasar ultraviolet continuum and emission lines, and probes of the Helium-II epoch of reionization at redshifts z = 2.5 to 3.3. We have also used COS "parallel observations" with the new Wide-Field Camera-3 to discover high-redshift galaxies likely responsible for hydrogen reionization at z = 7-8.