The supernova remnant SN 1006 as a Galactic particle accelerator

TL;DR

This study uses deep X-ray observations of SN 1006 to demonstrate that supernova remnants can efficiently accelerate cosmic rays, supporting the quasi-parallel acceleration mechanism and advancing understanding of cosmic ray origins.

Contribution

The paper provides observational evidence that SN 1006 efficiently accelerates cosmic rays and highlights the role of magnetic field orientation in this process.

Findings

SN 1006 is an efficient cosmic ray accelerator.

Post-shock density exceeds standard shock predictions.

Acceleration mechanism is likely quasi-parallel.

Abstract

The origin of cosmic rays is a pivotal open issue of high-energy astrophysics. Supernova remnants are strong candidates to be the Galactic factory of cosmic rays, their blast waves being powerful particle accelerators. However, supernova remnants can power the observed flux of cosmic rays only if they transfer a significant fraction of their kinetic energy to the accelerated particles, but conclusive evidence for such efficient acceleration is still lacking. In this scenario, the shock energy channeled to cosmic rays should induce a higher post-shock density than that predicted by standard shock conditions. Here we show this effect, and probe its dependence on the orientation of the ambient magnetic field, by analyzing deep X-ray observations of the Galactic remnant of SN 1006. By comparing our results with state-of-the-art models, we conclude that SN 1006 is an efficient source of cosmic rays and obtain an observational support for the quasi-parallel acceleration mechanism.