2016A&A...590A.128R -
Astronomy and Astrophysics, volume 590A128-128 (2016/6-1)
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.
RAUCH T., QUINET P., HOYER D., WERNER K., RICHTER P., KRUK J.W. and DEMLEITNER M.
Abstract (from CDS):
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 KrIV-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 KrIV-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 RE 0503-289.
Results. We reanalyzed the effective temperature and surface gravity and determined Teff=70000±2000K and log(g/cm/s2)=7.5±0.1. We newly identified ten KrV lines and one KrVI line in the spectrum of RE 0503-289. We measured a Kr abundance of -3.3±0.3 (logarithmic mass fraction). We discovered that the interstellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40km/s<vrad<+18km/s.
Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE stellar-atmosphere modeling. Observed KrV-VII line profiles in the UV spectrum of the white dwarf RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths.
Abstract Copyright:
© ESO, 2016
Journal keyword(s):
atomic data - line: identification - stars: abundances - stars: individual: RE 0503-289 - virtual observatory tools - stars: individual: RE 0457-281
Simbad objects:
3
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