Stellar laboratories. III. New Ba v, Ba vi, and Ba vii oscillator strengths and the barium abundance in the hot white dwarfs G191-B2B and RE 0503-289
Abstract
Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation.
Aims: Reliable Ba v-vii oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf
Methods: We newly calculated Ba v-vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of
Results: For the first time, we identified highly ionized Ba in the spectra of hot white dwarfs. We detected Ba vi and Ba vii lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of
Conclusions: Reliable measurements and calculations of atomic data are a pre-requisite for stellar-atmosphere modeling. Observed Ba vi-vii line profiles in two white dwarfs' (
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 2014
- DOI:
- 10.1051/0004-6361/201423878
- arXiv:
- arXiv:1404.6094
- Bibcode:
- 2014A&A...566A..10R
- Keywords:
-
- atomic data;
- line: identification;
- stars: abundances;
- stars: individual: G191;
- B2B;
- stars: individual: RE 0503;
- 289;
- virtual observatory tools;
- Astrophysics - Solar and Stellar Astrophysics;
- Physics - Atomic Physics
- E-Print:
- 36 pages, 8 figures