SNRs W28 and W44: old cosmic ray accelerators in molecular clouds

TL;DR

This paper models particle acceleration in old supernova remnants W28 and W44 using nonlinear shock acceleration theory, comparing results with radio and gamma-ray observations to understand cosmic ray acceleration in molecular clouds.

Contribution

It introduces a comprehensive nonlinear model of shock acceleration that incorporates hydrodynamics, shock modification, and streaming instability for these remnants.

Findings

Model successfully reproduces observed radio and gamma-ray spectra.

Highlights the role of shock modification in particle acceleration.

Provides insights into cosmic ray origins in molecular clouds.

Abstract

Nonlinear model of diffusive shock acceleration is used for investigation of the particle acceleration in old supernova remnants W28 and W44. We modeled the hydrodynamical evolution of the remnants, shock modification and streaming instability produced by accelerated particles. Comparison with available radio and gamma-ray data is given.