Implication of light metals (Li-Ca) on NLTE model atmospheres of compact hot stars
Received 7 August 1996 / Accepted 10 September 1996
We present an investigation about the influence of "light metals", i.e. lithium through calcium (elements 3 - 20), on structure and emergent fluxes of NLTE model atmospheres for hot compact stars (spectral type O with ).
In contrast to models which are composed only of H, He, C, N, and O, the models which include light metals have a strongly reduced EUV and X-ray flux. Thus, for the calculation of realistic fluxes in these wavelength bands, the inclusion of light metal opacities is indispensable.
The H I and He II line profiles in the optical wavelength range, which are commonly used for the determination of photospheric parameters like effective temperature, surface gravity, and He/H abundance ratio, are affected only marginally and only within their line cores. However, in the case of high resolution, high S/N spectra, these effects are detectable and thus, the light metals can not be neglected.
Key words: stars: atmospheres stars: early-type stars: general stars: fundamental parameters
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© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998