Camille Charignon (CEA), "A new mechanism for Deflagration to Detonation Transition (DDT) in thermonuclear supernovae"

jeudi 30 mai 2013, 14:00 → 15:00 Europe/Paris

LPNHE

Over the past 15 years, motivated by the fact that calibrated light curves of type Ia (or thermonuclear) supernovae have become an important tool to determine the expansion history of our Universe, considerable attention has been given to, both, observations and models of these events. The apparent homogeneity of these supernovae makes them powerful distance indicators. This also pointed towards a single progenitor for all thermonuclear supernovae. However, through recent comprehensive observational survey, what was originally thought to be a homogeneous class, turns out to be more and more heterogeneous, with subclasses presenting diverging properties. I will first give an overview of the evolving observational context and the resulting constraints, followed by a synthesis of the main explosion models that could potentially reproduce observations and the correct statistics. State of the art 3D simulations of the explosion can presently provide some valuable insights on the physical mechanism of the explosion. But there remains still a lot of unresolved physical scales, so they cannot provide by themselves a complete and coherent picture of the phenomenon. In this context, I will finally present a new physical model providing the long sought link between the two major modes of thermonuclear combustion in a SNIa, deflagrations and detonations. Due to numerical limitations, this mechanism has never emerged from full star simulations.

Slides Pres_Charignon.pdf