On the formation of C iii 4647-50-51 and C iii 5696 in O star atmospheres

  title={On the formation of C iii 4647-50-51 and C iii 5696 in O star atmospheres},
  author={Fabrice Martins and D. J. Hillier Lupm and CNRSMontpellier University and University of Pittsburgh},
  journal={Astronomy and Astrophysics},
We investigate the formation of CIII 4647-51-50 and CIII 5696 in the atmosphere of O stars to see if they can be reliably used for abundance determinations. We use atmosphere models computed with the code CMFGEN. The key physical ingredients explaining the formation of the CIII lines are extracted from comparisons of models with different stellar parameters and through examining rates controlling the level populations. The strength of CIII 5696 critically depends on UV CIII lines at 386, 574… 
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