Neutrino-driven supernova of a low-mass iron-core progenitor boosted by three-dimensional turbulent convection

TL;DR

This paper reports the first successful 3D simulation of a neutrino-driven supernova explosion from a low-mass iron-core star, revealing that 3D turbulence enhances explosion energy and alters shock dynamics compared to 2D models.

Contribution

It introduces a detailed 3D supernova simulation with advanced neutrino transport, demonstrating how 3D turbulence improves explosion conditions over 2D models.

Findings

3D models explode earlier with higher energy than 2D.

Lower temperatures in 3D reduce neutrino emission, aiding explosion.

Less vigorous accretion flows in 3D facilitate shock revival.

Abstract

We present the first successful simulation of a neutrino-driven supernova explosion in three dimensions (3D), using the Prometheus-Vertex code with an axis-free Yin-Yang grid and a sophisticated treatment of three-flavor, energy-dependent neutrino transport. The progenitor is a nonrotating, zero-metallicity 9.6 Msun star with an iron core. While in spherical symmetry outward shock acceleration sets in later than 300 ms after bounce, a successful explosion starts at ~130 ms postbounce in two dimensions (2D). The 3D model explodes at about the same time but with faster shock expansion than in 2D and a more quickly increasing and roughly 10 percent higher explosion energy of >10^50 erg. The more favorable explosion conditions in 3D are explained by lower temperatures and thus reduced neutrino emission in the cooling layer below the gain radius. This moves the gain radius inward and leads to a bigger mass in the gain layer, whose larger recombination energy boosts the explosion energy in 3D. These differences are caused by less coherent, less massive, and less rapid convective downdrafts associated with postshock convection in 3D. The less violent impact of these accretion downflows in the cooling layer produces less shock heating and therefore diminishes energy losses by neutrino emission. We thus have, for the first time, identified a reduced mass accretion rate, lower infall velocities, and a smaller surface filling factor of convective downdrafts as consequences of 3D postshock turbulence that facilitate neutrino-driven explosions and strengthen them compared to the 2D case.