Molecular Opacities: From Cool Stars to Planets

We want to improve, compute and test molecular opacities which are important for the atmospheres of cool astronomical objects like red giants, red and brown dwarfs or gas planets. In the case of C02 and C2 an ab initio calculation of a new line list should be performed. For CH4 and NH3 we will use a semi-empirical approach involving observational material in order to derive the opacity data. A water list that has been computed recently will also be investigated during this project. The effect of the new opacity data on the atmospheric structure will be tested using hydrostatic and dynamical models for cool stars and brown dwarfs. In addition, we will compute synthetic spectra for the visual and the infrared range and compare the results to corresponding observations.