21cm Intensity Mapping

Location: 
UCT, Maths Building, M320
Date: 
Thu, 27/02/2014 - 13:00 - 14:00
Speaker: 
Tzu-Ching Chang

The redshifted 21-cm emission from neutral hydrogen has emerged as a powerful probe for large-scale structure; a significant fraction of the observable universe can be mapped in the intensity mapping regime out to high redshifts. At redshifts around unity, the 21-cm emission traces the matter distribution and can be used to measure the Baryon Acoustic Oscillation (BAO) signature and constrain dark energy properties. I will describe our on-going observing program at the Green Bank Telescope (GBT), aiming to measure the 21cm power spectrum at z=0.8. A 800-MHz multi-beam focal-plane array for the GBT is currently under construction in order to facilitate a large-scale survey for BAO and the redshift-space distortion measurement for cosmological constraints. I will also describe spectral line Intensity Mapping in general, and how one can use CO and [CII] Intensity Mapping to help constrain reionization processes at 6