The Quasi-static Evolution of ONeMg Cores: Explosive Ignition Densities and the Collapse/Explosion Alternative
Abstract
The quasi-static evolution of an electron-degenerate ONeMg core is followed up to the point of explosive Ne-O ignition triggered by electron capture. Recently calculated electron-capture rates on 24Mg, 24Na, 20Ne, and 20F are used, and the ignition density is found to be about 8.5 x 10 exp 9 g/cu cm (when the Ledoux criterion for convection is adopted), instead of about 10 exp 10 g/cu cm as in earlier calculations. Such a comparatively low ignition density should lead to complete explosive disruption of the core even if the thermonuclear burning propagated all the way as a conductive, laminar flame. The dependence of the ignition density on the treatment adopted for mixing in the semiconvective region and the astronomical implications of our results are briefly discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1992
- DOI:
- 10.1086/186574
- Bibcode:
- 1992ApJ...398L..49C
- Keywords:
-
- Magnesium;
- Neon;
- Oxygen;
- Stellar Cores;
- Stellar Evolution;
- Supernovae;
- Electron Capture;
- Ignition;
- Nuclear Astrophysics;
- Stellar Mass;
- Astrophysics;
- STARS: INTERIORS;
- STARS: NEUTRON;
- STARS: SUPERNOVAE: GENERAL;
- STARS: WHITE DWARFS