AAO Colloquium


Wednesday 27 October 2010

3:30pm AAO Conference Room

The 21cm Forest

Katie Mack,   Kavli Institute/Institute for Astronomy, Cambridge

Future observations of the "21cm forest" against high-redshift radio sources will allow us to trace out the structure of neutral hydrogen in the pre-reionization intergalactic medium (IGM), provided bright radio sources can be found at sufficiently high redshift. I will present a calculation of the expected 21cm forest as might be observed in coming years and discuss the trade-off between the availability of large populations of high-redshift background radio sources and the requirement for the IGM to be sufficiently neutral for strong absorption in 21cm.