event
Monday 13 Dec 2010: D radiation-hydrodynamical simulations of the atmospheres of late-type stars
Dr. Wolfgang Hayek - University of Exeter, UK
Physics, 4th Floor interaction area 11:00-12:00
Numerical models of stellar atmospheres have a long tradition in astrophysics. Owing to the availability of large grids and the comparatively low computational effort, "classical" 1D models enjoy widespread use for many different purposes, such as spectral determination of stellar parameters and stellar abundance analyses. However, 1D atmosphere models of late-type stars suffer from severe shortcomings in the treatment of surface convection, which restricts their degree of realism and leads to discrepancies when compared to observations. In the last decades, 3D models of stellar surface convection have been created and continuously improved, based on a detailed description of hydrodynamical and radiative processes. The latest generation of solar atmosphere models is able to reproduce many observed properties of solar granulation with remarkable accuracy. I will give a brief description of the underlying physical assumptions of the models and show the results of various observational tests for the Sun. I will then discuss the important case of metal-poor giant stars, where 3D models are essential for obtaining a realistic description of the atmosphere.
