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SUMMARY:The Precision Array to Probe the Epoch of Reionization - Chris Car
 illi (NRAO\, USA)
DTSTART:20111115T163000Z
DTEND:20111115T173000Z
UID:TALK33446@talks.cam.ac.uk
CONTACT:David Titterington
DESCRIPTION:Cosmic reionization is the 'final frontier' in studies of cosm
 ic structure formation\, corresponding to the epoch when light from the fi
 rst stars and black holes act to reionize the neutral intergalactic medium
 \, a few hundred million years after the Big Bang. I will present a brief 
 review of the concept of reionization\, and exciting recent results that s
 et the first constraints on the epoch of reionization. The latest studies 
 of spectra of the most distant quasars suggest a substantially neutral IGM
  (> 10%) at z ~ 7. While revolutionary\, current measures of cosmic reioni
 zation have fundamental limitations (namely\, saturation at low neutral fr
 action). The most direct probe of the neutral IGM during reionization is t
 hrough the 21cm emission line of hydrogen. I will present the design and r
 ecent results from the Precision Array to Probe the Epoch of Reionization.
  PAPER comprises two low frequency dipole arrays (120 to 180 MHz) to study
  the HI 21cm signal from the neutral IGM during reionization: a 32 element
  engineering test array in Green Bank WV\, USA\, and a 128 element science
  array in the Karoo\, South Africa. Our design philosophy is to maintain w
 ell controlled and simple engineering specifications to mitigate the subst
 antial systematic problems that these measurements entail (strong continuu
 m foregrounds\, very wide fields\, large fractional bandwidths\, and stron
 g terrestrial interference). I will present the first all-sky images from 
 our working arrays in the Karoo and Green Bank\, details on the processing
  involved\, and plans for expansion to the full science array. If time all
 ows\, I will close with a few words on the prospects of intensity mapping 
 of the CO emission from the first galaxies\, to obtain the 'inverse view' 
 (relative to the HI 21cm studies) of the Cosmos during reionization\n
LOCATION:Martin Ryle Seminar Room\, Kavli Building
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