Chemical diagnostics of stellar physics: the physical and chemical properties of circumstellar environments around evolved stars as traced by molecules.

The aim of the proposed research is ot study the late stages of evolution of stars with initial mass between 0.6 and 8 solar masses. The goal is to probe the physical and chemical properties of the mass-loss process dominating the late evolution of the majority of stars in galaxies as our Milky Way. That way we will enhance our knowledge on the total enrichment of the interstellar medium by evolved stars. The study encompasses the analysis of a comprehensive set of molecular line diagnostics using a state-of-the-art theoretical radiative transfer code. The analysis of a set of molecular line profiles based on an extensive grid of 1 dimensional (1D) theoretical models typically takes several CPU-years. Extension to a 2D or 3D geometry enhances the computation time with a factor ~3 to 20. In addition, the reduction of some new high-technological observational data can only be done on a 64GB ram computer. The requested funding will be used as financial supply to buy 4 DELL PowerEdge servers with 64 GB ram, each with 2 Quad Core porcessors. One server costs 9100 euro, taxes included. These processors will be implemented in the existing network at the Instituut voor Sterrenkunde from the K.U.Leuven.

Keywords:Late evolutionary stages, Molecules, Infrared astronomy, Theoretical models, Observations

Disciplines:Astronomy and space sciences