The Three Dimensional Evolution to Core Collapse of a Massive Star

TL;DR

This paper presents the first 3D simulation of a massive star's final minutes before core collapse, highlighting the importance of non-spherical structures and turbulence in influencing supernova explosion mechanisms.

Contribution

It provides a novel 3D simulation of iron core collapse, including convection and turbulence, and assesses their impact on supernova explosion likelihood.

Findings

3D convection develops strong turbulence before collapse

Non-spherical structures significantly influence explosion mechanisms

Turbulent fluctuations favor neutrino-driven supernova explosions

Abstract

We present the first three dimensional (3D) simulation of the final minutes of iron core growth in a massive star, up to and including the point of core gravitational instability and collapse. We self-consistently capture the development of strong convection driven by violent Si burning in the shell surrounding the iron core. This convective burning builds the iron core to its critical (Chandrasekhar) mass and collapse ensues, driven by electron capture and photodisintegration. The non-spherical structure and motion (turbulent fluctuations) generated by 3D convection is substantial at the point of collapse. We examine the impact of such physically-realistic 3D initial conditions on the core-collapse supernova mechanism using 3D simulations including multispecies neutrino leakage. We conclude that non-spherical progenitor structure should not be ignored, and has a significant and favorable impact on the likelihood for neutrino-driven explosions.