Astrophysics, abstract
astro-ph/0609691

From: Friedrich Konrad Roepke [view email]

Date: Mon, 25 Sep 2006 21:33:12 GMT (304kb)

Surface detonation in type Ia supernova explosions?

Authors: F. K. Roepke (UCSC and MPA Garching), S. E. Woosley (UCSC)

Comments: 5 pages, 3 figures, in: Proceedings of the SciDAC 2006 Meeting, Denver June 25-26 2006, also available at this http URL

Journal-ref: Journal of Physics: Conference Series 46 (2006) 413-417

We explore the evolution of thermonuclear supernova explosions when the progenitor white dwarf star ignites asymmetrically off-center. Several numerical simulations are carried out in two and three dimensions to test the consequences of different initial flame configurations such as spherical bubbles displaced from the center, more complex deformed configurations, and teardrop-shaped ignitions. The burning bubbles float towards the surface while releasing energy due to the nuclear reactions. If the energy release is too small to gravitationally unbind the star, the ash sweeps around it, once the burning bubble approaches the surface. Collisions in the fuel on the opposite side increase its temperature and density and may -- in some cases -- initiate a detonation wave which will then propagate inward burning the core of the star and leading to a strong explosion. However, for initial setups in two dimensions that seem realistic from pre-ignition evolution, as well as for all three-dimensional simulations the collimation of the surface material is found to be too weak to trigger a detonation.

http://arxiv.org/abs/astro-ph/0609691