English

Theoretical He I Emissivities in the Case B Approximation

Astrophysics 2009-11-10 v1

Abstract

We calculate the He I case B recombination cascade spectrum using improved radiative and collisional data. We present new emissivities over a range of electron temperatures and densities. The differences between our results and the current standard are large enough to have a significant effect not only on the interpretation of observed spectra of a wide variety of objects but also on determinations of the primordial helium abundance.

Keywords

Cite

@article{arxiv.astro-ph/0502224,
  title  = {Theoretical He I Emissivities in the Case B Approximation},
  author = {R. L. Porter and R. P. Bauman and G. J. Ferland and K. B. MacAdam},
  journal= {arXiv preprint arXiv:astro-ph/0502224},
  year   = {2009}
}

Comments

Accepted to ApJL

R2 v1 2026-07-22T08:48:29.921Z