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.
Document Type
Article
Publication Date
3-10-2005
Digital Object Identifier (DOI)
http://dx.doi.org/10.1086/429370
Repository Citation
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.
https://uknowledge.uky.edu/physastron_facpub/94
Notes/Citation Information
Published in The Astrophysical Journal Letters, v. 622, no. 1, p. L73-L75.
© 2005. The American Astronomical Society. All rights reserved. Printed in the U.S.A.
The copyright holder has granted permission for posting the article here.