Eric Switzer (NASA GSFC): Measurements, prospects and challenges for line tomography after reionization

Seminar | August 7 | 3:10-4 p.m. | 501B Campbell Hall

 Eric Switzer, NASA GSFC

 Radio Astronomy Lab

Intensity mapping is an emerging approach that surveys the cumulative surface brightness of redshifted line radiation. It has parallels with both CMB and large-scale structure surveys, and a wide range of scientific goals from precision cosmology to galaxy evolution. I will describe a pathfinder survey for 21 cm mapping at z~1 using the Green Bank Telescope. A combined analysis of the 21 cm auto-power and Wigglez cross-power determines the HI abundance. The observations demonstrate foreground challenges and interpretations that are common to broader intensity mapping efforts. CO and CII line emission trace cold gas and star formation, so are compelling targets for dedicated intensity mapping surveys. Instruments originally designed for measurement of the CMB are well-matched to observation of these lines. I will describe prospects for PIXIE, a proposed CMB spectrometer.