Explosion Physics of Core-Collapse Supernovae

Abstract

The physical ingredients and processes ruling the violent death of a massive star are reviewed, from the collapse of its core to the birth of a neutron star and the ejection of the stellar envelope. The crucial phase of this transition results from the complex interplay of many fields of physics: quantum physics, gravitation, nuclear physics, neutrino physics, and magnetohydrodynamics. Recent numerical simulations have revealed the diversity of explosion paths induced by the diversity of progenitor structures. 3D simulations are now capable of exploring the consequences of pre-collapse asymmetries in the stellar core, such as the distribution of angular momentum, magnetic fields, and combustion inhomogeneities. They also revealed the limitations of the 2D results which assumed an axisymmetric evolution. Even with the fastest computers, physical approximations are still unavoidable to calculate neutrino transport. We describe the explosion physics based on the most robust results, privileging simplified descriptions conducive to the deepest physical understanding. We emphasize the role of hydrodynamical instabilities and their consequences on the nonspherical character of the explosion.