A Grid of NLTE Lineblanketed Model Atmospheres of Early BType Stars
Abstract
We have constructed a comprehensive grid of 1540 metal lineblanketed, NLTE, planeparallel, hydrostatic model atmospheres for the basic parameters appropriate to early Btype stars. The BSTAR2006 grid considers 16 values of effective temperatures, 15,000 K<=T_{eff}<=30,000 K with 1000 K steps, 13 surface gravities, 1.75<=logg<=4.75 with 0.25 dex steps, six chemical compositions, and a microturbulent velocity of 2 km s^{1}. The lower limit of logg for a given effective temperature is set by an approximate location of the Eddington limit. The selected chemical compositions range from twice to onetenth of the solar metallicity and metalfree. Additional model atmospheres for B supergiants (logg<=3.0) have been calculated with a higher microturbulent velocity (10 km s^{1}) and a surface composition that is enriched in helium and nitrogen and depleted in carbon. This new grid complements our earlier OSTAR2002 grid of Otype stars (our Paper I). The paper contains a description of the BSTAR2006 grid and some illustrative examples and comparisons. NLTE ionization fractions, bolometric corrections, radiative accelerations, and effective gravities are obtained over the parameter range covered by the grid. By extrapolating radiative accelerations, we have determined an improved estimate of the Eddington limit in absence of rotation between 55,000 and 15,000 K. The complete BSTAR2006 grid is available at the TLUSTY Web site.
 Publication:

The Astrophysical Journal Supplement Series
 Pub Date:
 March 2007
 DOI:
 10.1086/511270
 arXiv:
 arXiv:astroph/0611891
 Bibcode:
 2007ApJS..169...83L
 Keywords:

 Methods: Numerical;
 Radiative Transfer;
 Stars: Atmospheres;
 Stars: EarlyType;
 Astrophysics
 EPrint:
 50 pages