English

Testing common classical LTE and NLTE model atmosphere and line-formation codes for quantitative spectroscopy of early-type stars

Solar and Stellar Astrophysics 2015-06-03 v1

Abstract

It is generally accepted that the atmospheres of cool/lukewarm stars of spectral types A and later are described well by LTE model atmospheres, while the O-type stars require a detailed treatment of NLTE effects. Here model atmosphere structures, spectral energy distributions and synthetic spectra computed with ATLAS9/SYNTHE and TLUSTY/SYNSPEC, and results from a hybrid method combining LTE atmospheres and NLTE line-formation with DETAIL/SURFACE are compared. Their ability to reproduce observations for effective temperatures between 15000 and 35000 K are verified. Strengths and weaknesses of the different approaches are identified. Recommendations are made as to how to improve the models in order to derive unbiased stellar parameters and chemical abundances in future applications, with special emphasis on Gaia science.

Keywords

Cite

@article{arxiv.1111.1445,
  title  = {Testing common classical LTE and NLTE model atmosphere and line-formation codes for quantitative spectroscopy of early-type stars},
  author = {Norbert Przybilla and Maria-Fernanda Nieva and Keith Butler},
  journal= {arXiv preprint arXiv:1111.1445},
  year   = {2015}
}

Comments

12 pages, 8 figures; accepted for publication in Journal of Physics: Conference Series, GREAT-ESF Workshop: Stellar Atmospheres in the Gaia Era