Molecular Clouds as Cosmic Ray Laboratories

TL;DR

This paper discusses how gamma-ray emissions from molecular clouds can be used to study cosmic ray flux and diffusion in the galaxy, providing insights into cosmic ray propagation near supernova remnants.

Contribution

It introduces a method to use gamma-ray observations of molecular clouds to probe cosmic ray flux and diffusion coefficients in different galactic environments.

Findings

Gamma-ray emissions reveal cosmic ray flux in molecular clouds.

Analysis constrains cosmic ray diffusion coefficients.

Study distinguishes cosmic ray sources near supernova remnants.

Abstract

We will here discuss how the gamma-ray emission from molecular clouds can be used to probe the cosmic ray flux in distant regions of the Galaxy and to constrain the highly unknown cosmic ray diffusion coefficient. In particular we will discuss the GeV to TeV emission from runaway cosmic rays penetrating molecular clouds close to young and old supernova remnants and in molecular clouds illuminated by the background cosmic ray flux.