Thermonuclear Supernovae: Simulations of the Deflagration Stage and Their Implications

Large-scale three-dimensional numerical simulations of the deflagration stage of a thermonuclear supernova explosion show the formation and evolution of a highly convoluted turbulent flame in a gravitational field of an expanding carbon-oxygen white dwarf. The flame dynamics is dominated by the gravity-induced Rayleigh-Taylor instability that controls the burning rate. The thermonuclear deflagration releases enough energy to produce a healthy explosion. The turbulent flame, however, leaves large amounts of unburnt and partially burnt material near the star center, whereas observations imply these materials only in outer layers. This disagreement could be resolved if the deflagration triggers a detonation.