Theoretical He i Emissivities in the Case B Approximation

2005/02/10 by R. L. Porter, R. P. Bauman, G. J. Ferland +1 · 6 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #astro-ph

paper · pdf · doi:10.1086/429370

published as Astrophys.J. 622 (2005) L73 · Accepted to ApJL

arxiv created 2005/02/10 · openalex publication_date 2005/02/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01

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.

Citations

• Classical Electrodynamics, 3rd ed.
• CLOUDY 90: Numerical Simulation of Plasmas and Their Spectra

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