Concepedia

Supernova mechanisms

Reviews of Modern Physics · 1990 · 1.1K citations · 171 references

TL;DR

Type II supernovae mark the terminal evolution of massive stars, where an iron core exceeding the Chandrasekhar limit collapses in a fraction of a second, producing an outward shock that typically fails to eject the stellar envelope, so neutrino absorption by surrounding material is thought to revive the shock. The study aims to elucidate the supernova mechanism by determining the equation of state under the extreme densities and temperatures present during core collapse. The authors analyze SN 1987A observations and theoretical models to characterize pre‑collapse conditions and neutrino emission from the collapsed core.

Abstract

Supernovae of Type II occur at the end of the evolution of massive stars. The phenomenon begins when the iron core of the star exceeds a Chandrasekhar mass. The collapse of that core under gravity is well understood and takes a fraction of a second. To understand the phenomenon, a detailed knowledge of the equation of state at the relevant densities and temperatures is required. After collapse, the shock wave moves outward, but probably does not succeed in expelling the mass of the star. The most likely mechanism to do so is the absorption of neutrinos from the core by the material at medium distances. Observations and theory connected with SN 1987A are discussed, as are the conditions just before collapse and the emission of neutrinos by the collapsed core.