AAS 197, January 2001
Session 78. Nearby Galaxies I
Display, Wednesday, January 10, 2001, 9:30am-7:00pm, Exhibit Hall

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[78.12] A New Grid of NLTE Model Atmospheres of Hot Stars

I. Hubeny (AURA, GSFC), T. Lanz (U. Maryland, GSFC)

We briefly describe improvements in our non-LTE model atmosphere code, TLUSTY. The upgrades include opacity sampling, improved Fe collisional strengths, resonance-averaged photoionization cross-sections, and a number of numerical enhancements.

Using TLUSTY, version 200, we have calculated a grid of NLTE, fully-blanketed, model atmospheres covering the range of O to early B-type stars ( 20000 \leq T\rm eff \leq 55000\,K, 3.0 \leq \log g \leq 4.75) with a solar or 1/5 solar metallicity. The models incorporate over 70,000 NLTE atomic levels of about 30 ions of H, He, C, N, O, Ne, Mg, Si, S, Fe and Ni, which are grouped into about 700 superlevels. We compare our predicted EUV fluxes to other existing grids of model atmospheres (Atlas9, CoStar models), as well as to actual UV and optical observations of representative stars.

The author(s) of this abstract have provided an email address for comments about the abstract: hubeny@tlusty.gsfc.nasa.gov

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