Is the detonation burning in a degenerate carbonoxygen core of a presupernova possible?
Abstract
An attempt is made to solve the problem of the regime of burning in degenerate carbonoxygen cores (CO cores) of stars, which are assumed to be typeIa presupernovae, in favor of deflagration burning. For this purpose, we demonstrate numerically for ChapmanJouguet detonation waves the galloping instability that changes into decay. The structure of these waves is described by the ZeldovichNeumann model involving the kinetics of nuclear reactions in the burning zone. Along with the numerical hydrodynamic model, which include the kinetics of nuclear reactions, we suggest a qualitative model of galloping instability, which takes nonlinear perturbations into account. It is shown that the decay takes a very short time (less than 10 ms) and is nearly independent of th e initial disposition of detonation waves along the radius of the CO core. The kinetic equations include 12 nuclides, from C12 to Si28, with fairly detailed net of nuclear reactions (39 reactions). The initial composition of the CO core is an equimolar mixture of C12 and O16 (with equal mass fractions), while the mass of the CO core is close to the Chandrasekhar limit. In addition to with the mixture of Boltzmann nuclide gases, the equation of state takes into account the relativistic electronpositron gas of arbitrary degree of degeneracy and the equilibrium radiation.
 Publication:

Astronomy Letters
 Pub Date:
 April 1999
 Bibcode:
 1999AstL...25..206I