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Experimental and theoretical oscillator strengths of Mg i for accurate abundance analysis

Pehlivan Rhodin, Asli LU ; Hartman, Henrik LU ; Nilsson, Hampus LU and Jönsson, Per LU (2017) In Astronomy and Astrophysics 598.
Abstract
Context. With the aid of stellar abundance analysis, it is possible to study the galactic formation and evolution. Magnesium is an important element to trace the α-element evolution in our Galaxy. For chemical abundance analysis, such as magnesium abundance, accurate and complete atomic data are essential. Inaccurate atomic data lead to uncertain abundances and prevent discrimination between different evolution models.
Aims: We study the spectrum of neutral magnesium from laboratory measurements and theoretical calculations. Our aim is to improve the oscillator strengths (f-values) of Mg i lines and to create a complete set of accurate atomic data, particularly for the near-IR region.
Methods: We derived oscillator strengths by... (More)
Context. With the aid of stellar abundance analysis, it is possible to study the galactic formation and evolution. Magnesium is an important element to trace the α-element evolution in our Galaxy. For chemical abundance analysis, such as magnesium abundance, accurate and complete atomic data are essential. Inaccurate atomic data lead to uncertain abundances and prevent discrimination between different evolution models.
Aims: We study the spectrum of neutral magnesium from laboratory measurements and theoretical calculations. Our aim is to improve the oscillator strengths (f-values) of Mg i lines and to create a complete set of accurate atomic data, particularly for the near-IR region.
Methods: We derived oscillator strengths by combining the experimental branching fractions with radiative lifetimes reported in the literature and computed in this work. A hollow cathode discharge lamp was used to produce free atoms in the plasma and a Fourier transform spectrometer recorded the intensity-calibrated high-resolution spectra. In addition, we performed theoretical calculations using the multiconfiguration Hartree-Fock program ATSP2K.
Results: This project provides a set of experimental and theoretical oscillator strengths. We derived 34 experimental oscillator strengths. Except from the Mg i optical triplet lines (3p 3P°0,1,2-4s 3S1), these oscillator strengths are measured for the first time. The theoretical oscillator strengths are in very good agreement with the experimental data and complement the missing transitions of the experimental data up to n = 7 from even and odd parity terms. We present an evaluated set of oscillator strengths, gf, with uncertainties as small as 5%. The new values of the Mg i optical triplet line (3p 3P°0,1,2-4s 3S1) oscillator strength values are 0.08 dex larger than the previous measurements. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
atomic data, methods:laboratory:atomic, techniques:spectroscopic
in
Astronomy and Astrophysics
volume
598
publisher
EDP Sciences
external identifiers
  • scopus:85012225001
  • wos:000394465000101
ISSN
1432-0746
DOI
10.1051/0004-6361/201629849
language
English
LU publication?
yes
id
0e1bab19-1ea8-465b-8e31-57d90892c934
date added to LUP
2017-02-23 09:34:55
date last changed
2018-01-14 04:30:27
@article{0e1bab19-1ea8-465b-8e31-57d90892c934,
  abstract     = {Context. With the aid of stellar abundance analysis, it is possible to study the galactic formation and evolution. Magnesium is an important element to trace the α-element evolution in our Galaxy. For chemical abundance analysis, such as magnesium abundance, accurate and complete atomic data are essential. Inaccurate atomic data lead to uncertain abundances and prevent discrimination between different evolution models. <br/>Aims: We study the spectrum of neutral magnesium from laboratory measurements and theoretical calculations. Our aim is to improve the oscillator strengths (f-values) of Mg i lines and to create a complete set of accurate atomic data, particularly for the near-IR region. <br/>Methods: We derived oscillator strengths by combining the experimental branching fractions with radiative lifetimes reported in the literature and computed in this work. A hollow cathode discharge lamp was used to produce free atoms in the plasma and a Fourier transform spectrometer recorded the intensity-calibrated high-resolution spectra. In addition, we performed theoretical calculations using the multiconfiguration Hartree-Fock program ATSP2K. <br/>Results: This project provides a set of experimental and theoretical oscillator strengths. We derived 34 experimental oscillator strengths. Except from the Mg i optical triplet lines (3p 3P°0,1,2-4s 3S1), these oscillator strengths are measured for the first time. The theoretical oscillator strengths are in very good agreement with the experimental data and complement the missing transitions of the experimental data up to n = 7 from even and odd parity terms. We present an evaluated set of oscillator strengths, gf, with uncertainties as small as 5%. The new values of the Mg i optical triplet line (3p 3P°0,1,2-4s 3S1) oscillator strength values are 0.08 dex larger than the previous measurements.},
  articleno    = {A102},
  author       = {Pehlivan Rhodin, Asli and Hartman, Henrik and Nilsson, Hampus and Jönsson, Per},
  issn         = {1432-0746},
  keyword      = {atomic data,methods:laboratory:atomic,techniques:spectroscopic},
  language     = {eng},
  publisher    = {EDP Sciences},
  series       = {Astronomy and Astrophysics},
  title        = {Experimental and theoretical oscillator strengths of Mg i for accurate abundance analysis},
  url          = {http://dx.doi.org/10.1051/0004-6361/201629849},
  volume       = {598},
  year         = {2017},
}