Stellar laboratories. IV. New Ga iv, Ga v, and Ga vi oscillator strengths and the gallium 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, advanced non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These atmospheres are strongly dependent on the reliability of the atomic data that are used to calculate them.
Aims: Reliable Ga iv-vi oscillator strengths are used to identify Ga lines in the spectra of the DA-type white dwarf
Methods: We newly calculated Ga iv-vi oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for analyzing of Ga lines exhibited in high-resolution and high-S/N UV observations of
Results: We unambiguously detected 20 isolated and 6 blended (with lines of other species) Ga v lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of
Conclusions: Reliable measurements and calculations of atomic data are a prerequisite for stellar-atmosphere modeling. The observed Ga iv-v line profiles in two white dwarf (
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 2015
- DOI:
- 10.1051/0004-6361/201425326
- arXiv:
- arXiv:1501.07751
- Bibcode:
- 2015A&A...577A...6R
- 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:
- 127 pages, 6 figures