a New Approach of the Deflagration to Detonation Transition in SNIa Thermonuclear Supernovae

A wide class of type Ia thermonuclear supernovae models relies on the transition from the subsonic deflagration combustion regime to the supersonic detonation regime of the carbon and oxygen mixture of an accreting white dwarf, near the Chandrasekhar mass. We show that this can actually be achieved in a cold C+O white dwarf near the Chandrasekhar mass, with seed sound waves of relatively low Mach number M ∼ 0.02. Moreover, even weaker perturbations, with velocity perturbations as low as M ∼ 0.003 can trigger a detonation wave in SNIa progenitors models wich include the presence of a thin helium surface layer.