Advanced

Theoretical oscillator strengths and hyperfine structure in HgII

Brage, Tomas LU ; Proffitt, C and Leckrone, DS (1999) In Astrophysical Journal 513(1). p.524-534
Abstract
We present a theoretical model ion for Hg II, including oscillator strengths and hyperfine structure constants for a large number of transitions and levels. Different computational models have been used, depending on the observability of the lines and their importance in spectral synthesis of stellar atmospheres. For the resonance lines, we use highly systematic, accurate, and fully relativistic multiconfiguration Dirac-Fock methods. These methods are well suited to an accurate treatment of both the relativistic problem and the strong correlation effects in this ion. The predicted gf-values are probably accurate to within a few percent. A larger number of transitions are treated with a more flexible, but less accurate, version of the... (More)
We present a theoretical model ion for Hg II, including oscillator strengths and hyperfine structure constants for a large number of transitions and levels. Different computational models have been used, depending on the observability of the lines and their importance in spectral synthesis of stellar atmospheres. For the resonance lines, we use highly systematic, accurate, and fully relativistic multiconfiguration Dirac-Fock methods. These methods are well suited to an accurate treatment of both the relativistic problem and the strong correlation effects in this ion. The predicted gf-values are probably accurate to within a few percent. A larger number of transitions are treated with a more flexible, but less accurate, version of the method. This is based on the idea of crosswise optimization to represent a number of states in the same calculation. The results are used in stellar atmosphere models, assuming local thermodynamic equilibrium (LTE), where a line-by-line investigation is important. A larger set of levels are treated with semiempirical methods, for use in large scale non-LTE calculations. The lower accuracy of these are well-suited to a more statistical treatment of the structure of the ion. We discuss the importance of a correct treatment of core-valence correlation and relativistic effects for predicting accurate oscillator strengths. These tend to reduce their values by as much as a factor of 2 for the resonance line. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
atomic data, relativity
in
Astrophysical Journal
volume
513
issue
1
pages
524 - 534
publisher
University of Chicago Press
external identifiers
  • wos:000080197500042
ISSN
0004-637X
DOI
10.1086/306826
language
English
LU publication?
yes
id
43f88c2f-8c97-4d0a-856f-5167fb3550ca (old id 3919492)
date added to LUP
2013-07-09 08:07:13
date last changed
2016-04-16 02:54:12
@article{43f88c2f-8c97-4d0a-856f-5167fb3550ca,
  abstract     = {We present a theoretical model ion for Hg II, including oscillator strengths and hyperfine structure constants for a large number of transitions and levels. Different computational models have been used, depending on the observability of the lines and their importance in spectral synthesis of stellar atmospheres. For the resonance lines, we use highly systematic, accurate, and fully relativistic multiconfiguration Dirac-Fock methods. These methods are well suited to an accurate treatment of both the relativistic problem and the strong correlation effects in this ion. The predicted gf-values are probably accurate to within a few percent. A larger number of transitions are treated with a more flexible, but less accurate, version of the method. This is based on the idea of crosswise optimization to represent a number of states in the same calculation. The results are used in stellar atmosphere models, assuming local thermodynamic equilibrium (LTE), where a line-by-line investigation is important. A larger set of levels are treated with semiempirical methods, for use in large scale non-LTE calculations. The lower accuracy of these are well-suited to a more statistical treatment of the structure of the ion. We discuss the importance of a correct treatment of core-valence correlation and relativistic effects for predicting accurate oscillator strengths. These tend to reduce their values by as much as a factor of 2 for the resonance line.},
  author       = {Brage, Tomas and Proffitt, C and Leckrone, DS},
  issn         = {0004-637X},
  keyword      = {atomic data,relativity},
  language     = {eng},
  number       = {1},
  pages        = {524--534},
  publisher    = {University of Chicago Press},
  series       = {Astrophysical Journal},
  title        = {Theoretical oscillator strengths and hyperfine structure in HgII},
  url          = {http://dx.doi.org/10.1086/306826},
  volume       = {513},
  year         = {1999},
}