Stellar model atmospheres with emphasis on velocity dynamics

Abstract

Recently a formalism for solving the open set of non-local hydrodynamic moment equations has been applied to the envelopes of A-stars by Kupka & Montgomery (2002). Tests on numerical simulations and selected properties derived from stellar spectra such as average surface velocities and velocity skewness have shown the applicability of this RSM approach. In addition, a variety of improvements over existing modeling standards have been developed within and around the AMS group at the Institute for Astronomy in Vienna during the last couple of years. For example, individual elemental abundance patterns (Piskunov & Kupka 2001) or stratification as an observed parameter (Shuliak et al. 2004) can be taken into account in our model atmospheres. Once the underlying programs, which currently operate as stand alone applications, are combined with a model atmosphere code, we will obtain a powerful and efficient tool that will allow us the investigation of a number of open problems in the physics of A-stars, such as more realistic models of the temperature gradients of cool CP2 stars.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html