Closing in on the sources of Galactic and extragalactic cosmic rays

TL;DR

This paper discusses the potential for upcoming particle astrophysics instruments to identify the sources of galactic and extragalactic cosmic rays, highlighting the progress and remaining uncertainties in the field.

Contribution

It proposes that new instrumentation will soon clarify the origins of cosmic rays, especially distinguishing galactic sources like supernova remnants from extragalactic origins.

Findings

Anticipation of new instruments revealing cosmic ray sources

Evidence strongly suggests supernova remnants as galactic sources

The extragalactic component's origins remain uncertain

Abstract

We speculate that a new generation of particle astrophysics instrumentation will reveal the enigmatic sources of cosmic rays prior to the one hundredth anniversary of their discovery by Hess in 1912. While only a "smoking gun'' is missing for the case that the galactic component of the cosmic ray spectrum originates in supernova remnants, deciphering the origin of the extragalactic component is still at a level of reading tea leaves.