Friedrich Röpke

Exploding stars in a computer -- numerical approaches to model Type Ia supernovae

Being among the brightest explosions in the Universe, Type Ia supernovae are fascinating astronomical events. Their importance for many fields of astrophysics and cosmology calls for a sound understanding of their physical explosion mechanism and recent  advances in numerical simulations contributed significantly here.

Improvements in numerical approaches as well as ever more powerful computational resources facilitated three-dimensional simulations of the explosion stage. Here, a degenerate white dwarf star is burned by a thermonuclear flame ignited near its center and accelerated by turbulence on its way outwards. Hydrodynamical simulations of this scenario is challenged by the vast range of relevant length scales - from the radius of the star to the thin flame it covers more than 11 orders of magnitude.

Therefore, efficient algorithms and techniques for handling the hydrodynamics, the flame propagation, turbulence effects, and nuclear reactions are essential for implementations and will be described in detail.

On this basis, a code in a Large Eddy Simulation (LES) approach is constructed which provides a self-consistent model  of thermonuclear turbulent combustion in Type Ia supernovae.