Galactic cosmic rays

Pasquale Blasi,E Prandini,S Toscano

doi:10.1051/epjconf/201510500002

Pasquale Blasi, E Prandini + Show 1 more

Open Access

https://doi.org/10.1051/epjconf/201510500002

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Abstract

The multi-facet nature of the origin of cosmic rays is such that some of the problems currently met in our path to describing available data are due to oversimplified models of CR acceleration and transport, and others to lack of knowledge of the physical processes at work in certain conditions. On the other hand, the phenomenology of cosmic rays, as arising from better observations, is getting so rich that it makes sense to try to distinguish the problems that derive from too simple views of Nature and those that are challenging the very foundations of the existing paradigms. Here I will briefly discuss some of these issues.

Highlights

The perceived complexity of a physical problem often depends on how close we observe it
There is little doubt that the motion of cosmic rays (CRs) throughout the Galaxy is generally diffusive in nature, and that diffusion occurs in an energy dependent manner so as to reproduce the fact that the nuclear secondary-to-primary ratios decrease with energy above a few tens GeV/n
We can say that there is a general understanding of the CR origin in the Galaxy, namely we do have a model for their acceleration (DSA) in supernova remnants (SNRs) shocks and we have an understanding of the transport of CRs through the Galaxy

Summary

Introduction

The perceived complexity of a physical problem often depends on how close we observe it. There is little doubt that the motion of CRs throughout the Galaxy is generally diffusive in nature, and that diffusion occurs in an energy dependent manner so as to reproduce the fact that the nuclear secondary-to-primary ratios decrease with energy above a few tens GeV/n At this level, we can say that there is a general understanding of the CR origin in the Galaxy, namely we do have a model for their acceleration (DSA) in SNR shocks and we have an understanding of the transport of CRs through the Galaxy.

Cosmic Ray acceleration

Cosmic Ray propagation

Discussion