Research objectives and content
The aim of this project is to include -for the first time- the complete envelope of a red supergiant into a three-dimensional numerical radiation-hydrodynamics model in order to investigate the structure and dynamics of its convective envelope. Modern inter-ferometric observations demonstrate the existence of large-scale surface structures on nearby supergiants such as Betelgeuse. The increasing quality of observations is in strong contrast to the low level of theoretical understanding of such structures. Numerical simulations, which are very successful in investigating and explaining solar type granulation, will be extended to the extreme case of red supergiants to perform the detailed study of their huge convective cells.
The following questions will be addressed:
.What is the appearance of convective structures in supergiants?
.Does it resemble solar type granulation or do convective "hot-spots" exist on their surface?
.How do convective cells interact with global pulsations?
.To what height can material "overshoot" into the outer photosphere? What is the relation between convection and the strong winds of supergiants?
Training content (objective, benefit and expected impact)
The possibility to work at the NBIfAFG is of crucial importance for the feasibility of this project since many members are experts on astrophysical hydrodynamics. Particular benefit will arise from the collaboration with Drs. Ake Nordlund, Hans-Gunter Ludwig, and Martin Asplund. A broadening of knowledge in numerical methods and programming techniques is expected, especially in the handling of massively parallel machines where the NBIfAFG group has ample experience. The time at the NBIfAFG is considered an important step towards the German Habilitation.
Links with industry / industrial relevance (22)