|Dusty Circumstellar Environments: MPI-AMRVAC Simulations
|459, 6th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2011)
|Keppens, R.; van Marle, A. J.; Meliani, Z.
|We highlight results obtained on multi-dimensional modeling of circumstellar environments, where stellar outflows interact mutually or with the surrounding interstellar medium. We use the MPI-AMRVAC code, able to handle Newtonian to relativistic gas and plasma dynamic scenarios. For circumstellar modeling, the code has been extended by coupling the hydro to (possibly multiple) pressureless dust species. The dynamics of pressureless dust poses ultimate challenges to grid-adaptive numerical simulations, as it allows for delta waves in its purest form.
We subsequently illustrate pure gas dynamic scenarios, where optically thin radiative losses combined with supersonic outflows cause complex instability dominated circumstellar bubbles. We comment on single star, as well as on binary system scenarios. In the latter, we focus on the wind collision front where distinctly different instabilities manifest themselves in different regions.
Finally, we show coupled gas-dust dynamical treatments, as case scenarios for dust-loaded stellar outflows, specifically for moving massive stars. This includes a detailed treatment for dust grains in the stellar wind, accounting for drag forces between dust and gas.