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Isotope structure of SmII as an indicator of r- vs. s-process nucleosynthesis

Lundqvist, Martin LU ; Wahlgren, Glenn LU and Hill, V. (2007) In Astronomy & Astrophysics 463(2). p.693-702
Abstract
Aims. The isotope composition of samarium provides a previously unexploited means of determining the r- versus s-process content of e. g. metal-poor stars. The seven stable isotopes of samarium can be divided into two groups, where in one group the r- process is the dominant production mechanism, while for the second group it is the s-process that is dominant. The center-of-gravity for spectral lines produced by these two groups are slightly shifted with respect to each other, where the heavier and most abundant isotopes are mainly produced by the r- process. This relative shift makes the line position dependent upon the content of r- and s-processed samarium. The isotope composition also affects the width and the shape of the line, making... (More)
Aims. The isotope composition of samarium provides a previously unexploited means of determining the r- versus s-process content of e. g. metal-poor stars. The seven stable isotopes of samarium can be divided into two groups, where in one group the r- process is the dominant production mechanism, while for the second group it is the s-process that is dominant. The center-of-gravity for spectral lines produced by these two groups are slightly shifted with respect to each other, where the heavier and most abundant isotopes are mainly produced by the r- process. This relative shift makes the line position dependent upon the content of r- and s-processed samarium. The isotope composition also affects the width and the shape of the line, making it narrower and slightly more asymmetric when the composition deviates from the solar system composition. Methods. The behaviour of Sm II lines in stellar spectra is studied using synthetic spectrum techniques with line data accounting for both isotope and hyperfine structure. Isotope shifts in 11 lines of Sm II have been measured from a laboratory spectrum obtained with a Fourier transform spectrometer. Hyperfine structure constants have been taken from the literature. Results. The new atomic data are applied to the spectrum of the metal-poor halo star CS 31082-001 and suggests that this star contains predominantly r- processed material. We also discuss the uncertainties involved in this type of high precision measurement. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
methods : analytical, abundances, nucleosynthesis, nuclear reactions, stars : individual : CS 31082-001, atomic data, line : profiles
in
Astronomy & Astrophysics
volume
463
issue
2
pages
693 - 702
publisher
EDP Sciences
external identifiers
  • wos:000244069700033
  • scopus:33847381969
ISSN
0004-6361
DOI
10.1051/0004-6361:20066231
language
English
LU publication?
yes
id
37ec9d4e-d197-4d25-9ebf-62d32cfad1fd (old id 674846)
date added to LUP
2007-12-13 14:46:49
date last changed
2017-07-09 04:26:25
@article{37ec9d4e-d197-4d25-9ebf-62d32cfad1fd,
  abstract     = {Aims. The isotope composition of samarium provides a previously unexploited means of determining the r- versus s-process content of e. g. metal-poor stars. The seven stable isotopes of samarium can be divided into two groups, where in one group the r- process is the dominant production mechanism, while for the second group it is the s-process that is dominant. The center-of-gravity for spectral lines produced by these two groups are slightly shifted with respect to each other, where the heavier and most abundant isotopes are mainly produced by the r- process. This relative shift makes the line position dependent upon the content of r- and s-processed samarium. The isotope composition also affects the width and the shape of the line, making it narrower and slightly more asymmetric when the composition deviates from the solar system composition. Methods. The behaviour of Sm II lines in stellar spectra is studied using synthetic spectrum techniques with line data accounting for both isotope and hyperfine structure. Isotope shifts in 11 lines of Sm II have been measured from a laboratory spectrum obtained with a Fourier transform spectrometer. Hyperfine structure constants have been taken from the literature. Results. The new atomic data are applied to the spectrum of the metal-poor halo star CS 31082-001 and suggests that this star contains predominantly r- processed material. We also discuss the uncertainties involved in this type of high precision measurement.},
  author       = {Lundqvist, Martin and Wahlgren, Glenn and Hill, V.},
  issn         = {0004-6361},
  keyword      = {methods : analytical,abundances,nucleosynthesis,nuclear reactions,stars : individual : CS 31082-001,atomic data,line : profiles},
  language     = {eng},
  number       = {2},
  pages        = {693--702},
  publisher    = {EDP Sciences},
  series       = {Astronomy & Astrophysics},
  title        = {Isotope structure of SmII as an indicator of r- vs. s-process nucleosynthesis},
  url          = {http://dx.doi.org/10.1051/0004-6361:20066231},
  volume       = {463},
  year         = {2007},
}