A new generation of MARCS stellar model atmospheres

In a collaborative project with K. Eriksson, B. Gustafsson, B. Plez (Montpellier) and U.G. Jørgensen (Copenhagen) we have come a long way with a project to produce the last Uppsala grid of plane-parallel and spherical LTE model atmospheres for late-type stars (T(eff) < 8500 K). (The next step will be hydrodynamical 3-dimensional model atmospheres in non-LTE.)

The new models incorporate a large part of the now extensive knowledge of continuous and line opacities of atoms and di- and polyatomic molecules. Edvardsson et al. (1993) demonstrated the large impact of the extensive theoretical metal line absorption data calculated by R. Kurucz (Cambridge, MA) on model atmospheres for solar-type stars. For cooler stars the impact of molecular lines are considerable, and new data for several important molecules have been produced and compiled for the project. The warmer models will be extensively used in the other projects described here, and a large grid of model atmospheres will be made available to all astronomers.

Latest update: June 2, 2000