Department of Physics & Astronomy

Fall 2008 Colloquia

 

Oliver Zahn

Oliver Zahn

Inaugural Fellow
Berkeley Center for Cosmological Physics
The 21cm Line as a Probe of Reionization and Cosmology
December 8, 2008, 4PM, Thornton 411

As the only known probe of cosmological developments between decoupling of the Cosmic Microwave Background and redshift 6, the hydrogen spin-flip transition has the potential to revolutionize our understanding the Universe's Dark Ages and Reionization. The majority of our Hubble volume should be observable in 21 cm, hence observations may reveal a wealth of information about fundamental cosmological parameters as well as properties of the first sources of radiation. In practice there are many challenges that are currently being tackled by experimenters, such as the orders-of-magnitude brighter galactic foregrounds and the computational requirements associated with doing radio-interferometry at multi-meter wavelengths. I will review our recent progress in predicting what the 21 cm signal will look like, and talk about ways of distilling cosmological information from future data. I will then focus on analytic and numerical modeling of the Epoch of Reionization (EoR) and discuss some of the unique statistical features imprinted into the 21 cm background by extended ionized regions.
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