Astrophysical Modeling - The Chemical Evolution of Protoplanetary Disks (TP $3$)

Principal Investigator: Prof. Dr. Th. Henning,
Max Planck Institute for Astronomy, Heidelberg
and
Investigator: D. Semenov,
Astrophysical Institute and University Observatory, Jena

Abstract:

During the first half of the project duration time, we developed a new opacity model relevant to the physical conditions, typical of protoplanetary disks, and studied how various opacity models may influence the hydrodynamics of such objects. In addition, a new comprehensive gas-grain chemistry model is implemented based on the UMIST $95$ astrochemical database and a new method to analyze and reduce chemical networks is introduced. Using this reduction technique, we investigated the possibility to reduce the number of chemical reactions and species in our chemical network under the physical conditions, typical of molecular cloud cores. We were able to compute abundances of e- and CO accurately with significantly reduced chemical networks in the case of pure gas-phase chemistry. We showed that reduction for the gas-grain chemistry involving dust surface reactions is of no practical use. A possible application of the reduced networks for e- could be a self-consistent modelling of the physical and chemical evolution of magnetized accretion disks.