Radiation backgrounds from the first sources and the redshifted 21 cm signal
Jonathan Pritchard (Caltech) - Nov. 6
PDF at 12:00 noon
Observations of the redshifted 21 cm line offer a promising probe of early
radiation backgrounds. Anisotropies in the 21 cm signal arise from
fluctuations in the IGM temperature, density, and neutral fraction
and through the Lyman alpha flux. These fluctuations contain a wealth of
information on the background radiation field at UV and X-ray frequencies.
Before reionization, spatial variation in the Lyman alpha flux from the
first sources imprints information about the source distribution on the
21 cm signal. Later, as the IGM is heated by X-rays, inhomogeneous heating
leads to gas temperature fluctuations whose detection could constrain the
luminosity and spectrum of the first X-ray sources. In this talk, I will
discuss theoretical models for both of these mechanisms and outline the
possiblities for detection with future experiments.
The seminar will be held in 544 Campbell Hall.
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