He/H for Cosmology: He recombination coefficients including fine structure and singlet-triplet mixing

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

The primordial abundance of helium and its subsequent production in stars are primarily determined from recombination lines in HII Regions. Accuracies better than a percent must be obtained to make definitive tests in cosmology. We report initial results of a reinvestigation of the helium and hydrogen recombination processes. Our work builds on previous studies by improving the physical treatment of radiative recombination and subsequent cascades. Our treatment explicitly includes fine structure and singlet-triplet mixing in the helium transition rates. We base our transition rates on the results of Drake( Atomic, Molecular, & Optical Physics Handbook, AIP Press, Woodbury New York, 1996 ). Previous studies of helium recombination were largely based on variational, hydrogenic or Coulomb approximation calculations that did not include magnetic and relativistic interactions, thus entailing an unknown degree of inaccuracy. Comparisons with previous calculations are presented along with an assessment of the remaining major uncertainties. This work was supported in part by NSF and NASA.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

He/H for Cosmology: He recombination coefficients including fine structure and singlet-triplet mixing does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with He/H for Cosmology: He recombination coefficients including fine structure and singlet-triplet mixing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and He/H for Cosmology: He recombination coefficients including fine structure and singlet-triplet mixing will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1267617

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.