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.
Digital Object Identifier (DOI)
Porter, R. L.; Bauman, R. P.; Ferland, Gary J.; and MacAdam, K. B., "Theoretical He I Emissivities in the Case B Approximation" (2005). Physics and Astronomy Faculty Publications. 94.