Mechanisms for the initiation of detonations in the degenerate matter of supernovae
Abstract
The mechanisms and critical conditions for the initiation of thermonuclear detonations in C-O stars are investigated using a statistical approach which takes into account small scale fluctuations of induction time (a time for the local development of the thermonuclear runaway) and describes the feedback between mean hydrodynamical flow and burning. Results suggest that both processes, the direct initiation and the transition from deflagration to detonation, can take place at certain conditions. The direct initiation of a detonation at the center of dense C-O white dwarfs was ruled out by the fact that spectra of Type Ia supernovae show presence of intermediate mass elements. Using this fact, a lower bound is derived for the amplitude of the spatial spectrum of temperature fluctuations inside the interior of massive degenerate Type Ia progenitors before explosion. The possibility of a 'delayed detonation' mode of SNIa explosions is discussed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1991
- Bibcode:
- 1991A&A...246..383K
- Keywords:
-
- Detonation;
- Hydrodynamics;
- Supernova Remnants;
- Supernovae;
- Thermonuclear Explosions;
- White Dwarf Stars;
- Carbon Stars;
- Deflagration;
- Flame Propagation;
- Oxygen;
- Shock Waves;
- Steady State;
- Thermal Conductivity;
- Astrophysics