Delayed detonations in full-star models of type Ia supernova explosions

¹ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
² Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA
³ Lehrstuhl für Astronomie, Universität Würzburg, Am Hubland, 97974 Würzburg, Germany

Received: 18 October 2006
Accepted: 12 December 2006

Abstract

Aims.We present the first full-star three-dimensional explosion simulations of thermonuclear supernovae including parameterized deflagration-to-detonation transitions that occur once the flame enters the distributed burning regime.

Methods.Treating the propagation of both the deflagration and the detonation waves in a common front-tracking approach, the detonation is prevented from crossing ash regions.

Results.Our criterion triggers the detonation wave at the outer edge of the deflagration flame and consequently it has to sweep around the complex structure and to compete with expansion. Despite the impeded detonation propagation, the obtained explosions show reasonable agreement with global quantities of observed type Ia supernovae. By igniting the flame in different numbers of kernels around the center of the exploding white dwarf, we set up three different models shifting the emphasis from the deflagration phase to the detonation phase. The resulting explosion energies and iron group element productions cover a large part of the diversity of type Ia supernovae.

Conclusions.Flame-driven deflagration-to-detonation transitions, if hypothetical, remain a possibility deserving further investigation.