The two alternative explosion mechanisms of core-collapse supernovae: 2024 status report

TL;DR

This paper compares two core-collapse supernova explosion mechanisms, arguing that the neutrino mechanism cannot account for observed energies or morphologies, and supports the jittering-jets mechanism as the primary process based on recent simulations and observations.

Contribution

It provides a critical analysis of the neutrino mechanism's limitations and advocates for the jittering-jets explosion mechanism as the primary driver of CCSNe.

Findings

Neutrino heating cannot supply the observed explosion energies.

Many observed supernova remnant morphologies are inconsistent with the neutrino mechanism.

Jittering jets are supported by morphological signatures in remnants.

Abstract

In comparing the two alternative explosion mechanisms of core-collapse supernovae (CCSNe), I examine recent three-dimensional (3D) hydrodynamical simulations of CCSNe in the frame of the delayed-neutrino explosion mechanism (neutrino mechanism) and argue that these valuable simulations show that neutrino heating can supply a non-negligible fraction of the explosion energy but not the observed energies, hence cannot be the primary explosion mechanism. In addition to the energy crisis, the neutrino mechanism predicts many failed supernovae that are not observed. The most challenging issue of the neutrino mechanism is that it cannot account for point-symmetric morphologies of CCSN remnants, many of which were identified in 2024. These contradictions with observations imply that the neutrino mechanism cannot be the primary explosion mechanism of CCSNe. The alternative jittering-jets explosion mechanism (JJEM) seems to be the primary explosion mechanism of CCSNe; neutrino heating boosts the energy of the jittering jets. Even if some simulations show explosions of stellar models (but usually with energies below observed), it does not mean that the neutrino mechanism is the explosion mechanism. Jittering jets, which simulations do not include, can explode the core before the neutrino heating process does. Morphological signatures of jets in many CCSN remnants suggest that jittering jets are the primary driving mechanism, as expected by the JJEM.