Gamma-ray astronomy as a milestone in the cosmic ray origin issue

Abstract

During the last years, high-energy astrophysics has not been considered at the same level as other scientific disciplines. In doing so, there is a very high risk neglecting the $$\gamma $$-ray energy band that has a strong importance to solve some still open issues. This paper is focused, in particular, on the galactic cosmic ray origin issue, and it shows how only a coexistence of low-energy (MeV–GeV) and high-energy (GeV–TeV) $$\gamma $$-ray instruments can allow us to solve this century-old issue.