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The FERRUM Project: Experimental transition probabilities of [Fe II] and astrophysical applications

Hartman, Henrik LU ; Derkatch, A.; Donnelly, M. P.; Gull, T.; Hibbert, A.; Johansson, Sveneric LU ; Lundberg, Hans LU ; Mannervik, S; Norlin, L.-O. and Rostohar, D., et al. (2003) In Astronomy & Astrophysics 397(3). p.1143-1149
Abstract
We report on experimental transition probabilities for thirteenforbidden [Fe II] lines originating from three different metastable FeIi levels. Radiative lifetimes have been measured of two metastablestates by applying a laser probing technique on a stored ion beam.Branching ratios for the radiative decay channels, i.e. M1 and E2transitions, are derived from observed intensity ratios of forbiddenlines in astrophysical spectra and compared with theoretical data. Thelifetimes and branching ratios are combined to derive absolutetransition probabilities, A-values.We present the first experimental lifetime values for the two Fe IIlevels a<SUP>4</SUP>G<SUB>9/2</SUB> and... (More)
We report on experimental transition probabilities for thirteenforbidden [Fe II] lines originating from three different metastable FeIi levels. Radiative lifetimes have been measured of two metastablestates by applying a laser probing technique on a stored ion beam.Branching ratios for the radiative decay channels, i.e. M1 and E2transitions, are derived from observed intensity ratios of forbiddenlines in astrophysical spectra and compared with theoretical data. Thelifetimes and branching ratios are combined to derive absolutetransition probabilities, A-values.We present the first experimental lifetime values for the two Fe IIlevels a<SUP>4</SUP>G<SUB>9/2</SUB> and b<SUP>2</SUP>H<SUB>11/2</SUB>and A-values for 13 forbidden transitions froma<SUP>6</SUP>S<SUB>5/2</SUB>, a<SUP>4</SUP>G<SUB>9/2</SUB> andb<SUP>4</SUP>D<SUB>7/2</SUB> in the optical region. A discrepancybetween the measured and calculated values of the lifetime for theb<SUP>2</SUP>H<SUB>11/2</SUB> level is discussed in terms of levelmixing. We have used the code CIV3 to calculate transitionprobabilities of the a<SUP>6</SUP>D-a<SUP>6</SUP>S transitions.We have also studied observational branching ratios for lines from 5other metastable Fe II levels and compared them to calculated values. Aconsistency in the deviation between calibrated observational intensityratios and theoretical branching ratios for lines in a wider wavelengthregion supports the use of [Fe II] lines for determination of reddening. (Less)
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publication status
published
subject
keywords
atomic data, stars: individual: Eta Carinae, ISM: dust, extinction
in
Astronomy & Astrophysics
volume
397
issue
3
pages
1143 - 1149
publisher
EDP Sciences
external identifiers
  • wos:000180249800041
  • scopus:0037249906
ISSN
0004-6361
DOI
10.1051/0004-6361:20021557
language
English
LU publication?
yes
id
7416faee-50c5-41ea-9ec3-0a405c0087b7 (old id 130609)
date added to LUP
2007-07-13 10:41:51
date last changed
2017-01-01 07:28:33
@article{7416faee-50c5-41ea-9ec3-0a405c0087b7,
  abstract     = {We report on experimental transition probabilities for thirteenforbidden [Fe II] lines originating from three different metastable FeIi levels. Radiative lifetimes have been measured of two metastablestates by applying a laser probing technique on a stored ion beam.Branching ratios for the radiative decay channels, i.e. M1 and E2transitions, are derived from observed intensity ratios of forbiddenlines in astrophysical spectra and compared with theoretical data. Thelifetimes and branching ratios are combined to derive absolutetransition probabilities, A-values.We present the first experimental lifetime values for the two Fe IIlevels a&lt;SUP&gt;4&lt;/SUP&gt;G&lt;SUB&gt;9/2&lt;/SUB&gt; and b&lt;SUP&gt;2&lt;/SUP&gt;H&lt;SUB&gt;11/2&lt;/SUB&gt;and A-values for 13 forbidden transitions froma&lt;SUP&gt;6&lt;/SUP&gt;S&lt;SUB&gt;5/2&lt;/SUB&gt;, a&lt;SUP&gt;4&lt;/SUP&gt;G&lt;SUB&gt;9/2&lt;/SUB&gt; andb&lt;SUP&gt;4&lt;/SUP&gt;D&lt;SUB&gt;7/2&lt;/SUB&gt; in the optical region. A discrepancybetween the measured and calculated values of the lifetime for theb&lt;SUP&gt;2&lt;/SUP&gt;H&lt;SUB&gt;11/2&lt;/SUB&gt; level is discussed in terms of levelmixing. We have used the code CIV3 to calculate transitionprobabilities of the a&lt;SUP&gt;6&lt;/SUP&gt;D-a&lt;SUP&gt;6&lt;/SUP&gt;S transitions.We have also studied observational branching ratios for lines from 5other metastable Fe II levels and compared them to calculated values. Aconsistency in the deviation between calibrated observational intensityratios and theoretical branching ratios for lines in a wider wavelengthregion supports the use of [Fe II] lines for determination of reddening.},
  author       = {Hartman, Henrik and Derkatch, A. and Donnelly, M. P. and Gull, T. and Hibbert, A. and Johansson, Sveneric and Lundberg, Hans and Mannervik, S and Norlin, L.-O. and Rostohar, D. and Royen, P. and Schef, P.},
  issn         = {0004-6361},
  keyword      = {atomic data,stars: individual: Eta Carinae,ISM: dust,extinction},
  language     = {eng},
  number       = {3},
  pages        = {1143--1149},
  publisher    = {EDP Sciences},
  series       = {Astronomy & Astrophysics},
  title        = {The FERRUM Project: Experimental transition probabilities of [Fe II] and astrophysical applications},
  url          = {http://dx.doi.org/10.1051/0004-6361:20021557},
  volume       = {397},
  year         = {2003},
}