Stellar laboratories. VII. New Kr iv - vii oscillator strengths and an improved spectral analysis of the hot, hydrogen-deficient DO-type white dwarf 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: New Kr iv-vii oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations.
Methods: We calculated Kr iv-vii oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf
Results: We reanalyzed the effective temperature and surface gravity and determined Teff = 70000 ± 2000 K and log (g/ cm s-2) = 7.5 ± 0.1. We newly identified ten Kr v lines and one Kr vi line in the spectrum of
Conclusions: Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE stellar-atmosphere modeling. Observed Kr v-vii line profiles in the UV spectrum of the white dwarf
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 2016
- DOI:
- 10.1051/0004-6361/201628131
- arXiv:
- arXiv:1603.00701
- Bibcode:
- 2016A&A...590A.128R
- Keywords:
-
- atomic data;
- line: identification;
- stars: abundances;
- stars:;
- individual: RE 0503;
- 289;
- virtual observatory tools;
- individual: RE 0457;
- 281;
- Astrophysics - Solar and Stellar Astrophysics;
- Physics - Atomic Physics
- E-Print:
- 30 pages, 17 figures