Atomic Hydrogen in Distant Galaxies

  title={Atomic Hydrogen in Distant Galaxies},
  author={Nissim Kanekar and Aditya Chowdhury and Jayaram N. Chengalur},
Atomic hydrogen is a fundamental constituent of galaxies, and is the primary fuel for star formation. Understanding how the atomic hydrogen content of galaxies evolves with time is thus critical to understanding galaxy evolution. In this article, we discuss how one measures the atomic hydrogen content of distant galaxies, and what these measurements tell us about the evolution of our Universe. 
1 Citations
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  • J N Chengalur et al., Hi 21-centimetre emission from an ensemble of galaxies at an average redshift of one, Nature, 586, 369
  • 2020
Dark Matter: What you see ain't what you got
  • 1999
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  • 1999