Core-collapse Supernovae as Cosmic Ray Sources

TL;DR

This paper investigates how core-collapse supernovae can accelerate cosmic rays to very high energies through shock-driven instabilities, leading to significant magnetic field amplification and rapid particle acceleration.

Contribution

It provides a self-similar model to calculate CR-driven instability growth timescales and demonstrates the potential for supernova shocks to produce PeV cosmic rays within days.

Findings

CR-driven instabilities can grow rapidly in supernova shocks

Magnetic fields can be amplified by up to 50% of observed values

CRs can reach energies of 1-10 PeV within days after shock breakout

Abstract

Core-collapse supernovae produce fast shocks which expand into the dense circumstellar medium (CSM) of the stellar progenitor. Cosmic rays (CRs) accelerated at these shocks can induce the growth of electromagnetic fluctuations in the pre-shock medium. Using a self-similar description for the shock evolution, we calculate the growth time-scales of CR driven instabilities for SNe in general, and SN 1993J in particular. We find that extended SN shocks can trigger fast intra-day instabilities, strong magnetic field amplification, and CR acceleration. In particular, the non-resonant streaming instability can contribute to about 50 per cent of the magnetic field intensity deduced from radio data. This results in the acceleration of CR particles to energies of 1-10 PeV within a few days after the shock breakout.