Philipp Mertsch
Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, Aachen, Germany
Cosmic rays coming of age
Cosmic rays (CRs) are messengers of the violent universe and interpretations of CR measurements can be used to infer the properties of such environments as far as overall energetics, structure and dynamics are concerned. In addition, CRs have a dynamical effect in a variety of environments, shaping not only the medium that they themselves travel in, but also affecting other constituents, e.g. magnetic fields, radiation and the thermal gas. We will review the status of Galactic CRs as of mid/late 2021, both from the observational and the theoretical side. We will summarise the new data from space-borne experiments on CR electrons and positrons, proton and helium as well as heavier nuclei and their isotopes. We will cover a couple of novel aspects in the modeling of acceleration of CRs at non-relativistic shocks and in their feedback on Galactic scales.