Black hole formation and fallback during the supernova explosion of a $40 \,\mathrm{M}_\odot$ star

TL;DR

This paper presents the first 3D simulation of black hole formation and fallback during a supernova explosion of a 40 solar mass star, revealing how neutrino-heated bubbles can survive and influence explosion dynamics.

Contribution

It introduces a novel combined simulation approach using CoCoNuT-FMT and Arepo codes to model BH formation and fallback in supernovae, providing new insights into explosion mechanics.

Findings

Neutrino-heated bubbles can survive for tens of seconds after BH formation.

Approximately 11 solar masses of hydrogen are expelled with 0.23 Bethe energy.

The resulting black hole has modest kick and spin, with potential for stronger effects in other scenarios.

Abstract

Fallback in core-collapse supernovae is considered a major ingredient for explaining abundance anomalies in metal-poor stars and the natal kicks and spins of black holes (BHs). We present a first 3D simulation of BH formation and fallback in an "aborted" neutrino-driven explosion of a $40$ solar mass zero-metallicity progenitor from collapse to shock breakout. We follow the phase up to BH formation using the relativistic CoCoNuT-FMT code. For the subsequent evolution to shock breakout we apply the moving-mesh code Arepo to core-collapse supernovae for the first time. Our simulation shows that despite early BH formation, neutrino-heated bubbles can survive for tens of seconds before being accreted, leaving them sufficient time to transfer part of their energy to sustain the shock wave as is propagates through the envelope. Although the initial net energy ($\sim 2$ Bethe) of the neutrino-heated ejecta barely equals the binding energy of the envelope, $11\,\mathrm{M}_\odot$ of hydrogen are still expelled with an energy of $0.23$ Bethe. We find no significant mixing and only a modest BH kick and spin, but speculate that stronger effects could occur for slightly more energetic explosions or progenitors with less tightly bound envelopes.