The Fundamentals of the 21-cm Line
arXiv:1909.13740
Abstract
We review some of the fundamental physics necessary for computing the highly-redshifted spin-flip background. We first discuss the radiative transfer of the 21-cm line and define the crucial quantities of interest. We then review the processes that set the spin temperature of the transition, with a particular focus on Wouthuysen-Field coupling, which is likely to be the most important process during and after the Cosmic Dawn. Finally, we discuss processes that heat the intergalactic medium during the Cosmic Dawn, including the scattering of Lyman-alpha, cosmic microwave background, and X-ray photons.
arXiv commentTo appear as a book chapter in "The Cosmic 21-cm Revolution: Charting the first billion years of our Universe," Ed Andrei Mesinger (Bristol: IOP Publishing Ltd) AAS-IOP ebooks http://www.iopscience.org/books/aas. arXiv admin note: text overlap with arXiv:astro-ph/0608032
References in corpus (6)
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