Galactic structure (of the Milky Way and in the Near Universe)

Nucleosynthesis of heavy elements

Thomas Rauscher, R. Hirschi (Keele), Chiaki Kobayashin

Understanding the origin of the elements and the production of nuclides throughout the Galactic history in various astrophysical sites requires interdisciplinary research combining the fields of astrophysics, astronomy, nuclear and particle physics. In this context we are offering a PhD project concerned with modelling of hydrostatic and explosive phases of stellar evolution and emphasis on their nucleosynthesis. The student will perform computations with stellar models and post-processing reaction networks. Variations in the patterns of produced nuclei stemming from uncertainties in the nuclear input will be explored. Comparison to observational data further constrains the models. In order to obtain a larger picture of the global impact, this will be tied to Galactic Chemical Evolution models to investigate their sensitivity to nuclear and stellar model uncertainties. The project requires a sound theoretical and astrophysical background on the Master level, good computation skills, knowledge of FORTRAN90/95 and Python and familiarity with working in a Linux command-line environment.

Astrophysical reaction rates for heavy element nucleosynthesis

T. Rauscher, S. G. Ryan, F.-K. Thielemann (U Basel, Switzerland)

Understanding the origin of the elements and the production of nuclides throughout the Galactic history in various astrophysical sites requires interdisciplinary research combining the fields of theoretical astrophysics and nuclear physics. In this context we are offering a project with emphasis on modelling nuclear reactions in stellar and explosive environments. Astrophysical reaction rates are key quantities to understand nucleosynthesis. Nuclear reactions proceed differently in astrophysical plasmas than in the laboratory and additional effects have to be considered. The majority of isotopes created in explosive nucleosynthesis is very short-lived and cannot be studied experimentally at all. Model predictions of nuclear reactions are therefore essential. The project involves the implementation of previously unconsidered effects and improved knowledge of nuclear properties into existing reaction models, and to test the new predictions in comparison with the scarce experimental data. The impact of the results on production of nuclei in various astrophysical environments - stars, supernovae, explosive nuclear burning on the surface of a neutron star - will be studied in post-processing reaction networks. The project requires a sound background in theoretical nuclear physics on the Master level, good computation skills, knowledge of FORTRAN90/95 and Python and familiarity with working in a Linux command-line environment.