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New Results from the Cosmic Origins Spectrograph: Missing Baryons, AGN, and Reionization

Event Details

Event Dates: 

Monday, August 26, 2013 - 10:00am

Seminar Location: 

  • JILA Auditorium

Speaker Name(s): 

Michael Shull

Speaker Affiliation(s): 

University of Colorado
Seminar Type/Subject

Scientific Seminar Type: 

  • Astrophysical & Planetary Sciences Seminar

Event Details & Abstract: 

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 circumgalactic medium (CGM), 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 (see figure), measurements of heavy elements in galactic halos, 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.