Multiwavelength Signatures of Cosmic Ray Acceleration by Young Supernova Remnants

TL;DR

This paper reviews multiwavelength observations of young supernova remnants, highlighting signatures of efficient cosmic ray acceleration such as magnetic field amplification, low plasma temperatures, and high post-shock compression.

Contribution

It provides a comprehensive overview of observational evidence supporting cosmic ray acceleration in young supernova remnants, emphasizing spectroscopic signatures.

Findings

Magnetic field amplification observed via X-ray spectroscopy

Lower post-shock temperatures indicating efficient cosmic ray acceleration

High post-shock compression factors in some remnants

Abstract

An overview is given of multiwavelength observations of young supernova remnants, with a focus on the observational signatures of efficient cosmic ray acceleration. Some of the effects that may be attributed to efficient cosmic ray acceleration are the radial magnetic fields in young supernova remnants, magnetic field amplification as determined with X-ray imaging spectroscopy, evidence for large post-shock compression factors, and low plasma temperatures, as measured with high resolution optical/UV/X-ray spectroscopy. Special emphasis is given to spectroscopy of post-shock plasma's, which offers an opportunity to directly measure the post-shock temperature. In the presence of efficient cosmic ray acceleration the post-shock temperatures are expected to be lower than according to standard equations for a strong shock. For a number of supernova remnants this seems indeed to be the case.