English

Intergalactic heating by Lyman-alpha photons including hyperfine structure corrections

Cosmology and Nongalactic Astrophysics 2021-06-01 v1

Abstract

Lyman-alpha photons from the first radiating sources in the Universe play a pivotal role in 21-cm radio detections of Cosmic Dawn and the Epoch of Reionization. Comments are provided on the effect of the hyperfine structure of hydrogen on the rate of heating or cooling of the Intergalactic Medium. It is shown that heating of the still neutral hydrogen by the Cosmic Microwave Background is negligible, with a characteristic heating time of 1e27 s/ (1+z) at redshift z.

Keywords

Cite

@article{arxiv.2105.14516,
  title  = {Intergalactic heating by Lyman-alpha photons including hyperfine structure corrections},
  author = {A. Meiksin},
  journal= {arXiv preprint arXiv:2105.14516},
  year   = {2021}
}

Comments

Accepted for publication in Research Notes of the AAS. (Missing reference added.)

R2 v1 2026-06-24T02:37:53.681Z