Non-LTE Line-Blanketed Model Atmospheres of B-type Stars
Abstract
We present an extension of our OSTAR2002 grid of NLTE model atmospheres to B-type stars. We have calculated over 1,300 metal line-blanketed, NLTE, plane-parallel, hydrostatic model atmospheres for the basic parameters appropriate to B stars. The grid covers 16 effective temperatures from 15,000 to 30,000 K, with 1000 K steps, 13 surface gravities, log g≤ 4.75 down to the Eddington limit, and 5 compositions (2, 1, 0.5, 0.2, and 0.1 times solar). We have adopted a microturbulent velocity of 2 km/s for all models. In the lower surface gravity range (log g≤ 3.0), we supplemented the main grid with additional model atmospheres accounting for higher microtutbulent velocity (10 km/s) and for alterated surface composition (He and N-rich, C-deficient), as observed in B supergiants. The models incorporate basically all known atomic levels of 46 ions of H, He, C, N, O, Ne, Mg, Al, Si, S, and Fe, which are grouped into 1127 superlevels. Models and spectra will be available at our Web site, http://nova.astro.umd.edu.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2005
- Bibcode:
- 2005AAS...20718221L