Recent developments in cosmic ray physics

Abstract

The search for a theory of the origin of cosmic rays that may be considered as a standard, agreeable model is still ongoing. On one hand, much circumstantial evidence exists of the fact that supernovae in our Galaxy play a crucial role in producing the bulk of cosmic rays observed on Earth. On the other hand, important questions about their ability to accelerate particles up to the knee remain unanswered. The common interpretation of the knee as a feature coinciding with the maximum energy of the light component of cosmic rays and a transition to a gradually heavier mass composition is mainly based on KASCADE results. Some recent data appear to question this finding: YAC1 - Tibet Array and ARGO-YBJ find a flux reduction in the light component at $\sim 700$ TeV, appreciably below the knee. Whether the maximum energy of light nuclei is as high as $3000$ TeV or rather as low as a few hundred TeV has very important consequences on the supernova remnant paradigm for the origin of cosmic rays, as well on the crucial issue of the transition from Galactic to extragalactic cosmic rays. In such a complex phenomenological situation, it is important to have a clear picture of what is really known and what is not. Here I will discuss some solid and less solid aspects of the theory (or theories) for the origin of cosmic rays and the implications for future searches in this field.

Invited Review Talk in "Cosmic Ray Origin - Beyond the Standard Models", San Vito di Cadore (BL), Italy 16-22 March 2014

References in corpus (17)

• Detection of the Characteristic Pion-Decay Signature in Supernova Remnants
• Primary particle acceleration above 100 TeV in the shell-type Supernova Remnant RX J1713.7-3946 with deep H.E.S.S. observations
• Spectral breaks as a signature of cosmic ray induced turbulence in the Galaxy
• Observations of the young supernova remnant RX J1713.7-3946 with the Fermi Large Area Telescope
• Origin of the Cosmic Ray Spectral Hardening
• Non linear particle acceleration at non-relativistic shock waves in the presence of self-generated turbulence
• Spectrum of cosmic rays, produced in supernova remnants
• A dip in the UHECR spectrum and the transition from galactic to extragalactic cosmic rays
• Ankle-like Feature in the Energy Spectrum of Light Elements of Cosmic Rays Observed with KASCADE-Grande
• Dynamical Feedback of Self-generated Magnetic Fields in Cosmic Ray Modified Shocks
• Gamma ray emission from SNR RX J1713.7-3946 and the origin of galactic cosmic rays
• Modeling Bell's Non-resonant Cosmic Ray Instability
• Constraints on the origin of cosmic rays above $10^{18}$ eV from large scale anisotropy searches in data of the Pierre Auger Observatory
• AGILE detection of GeV gamma-ray emission from the SNR W28
• Dynamical effects of self-generated magnetic fields in cosmic ray modified shocks
• Turbulence Dissipation and Particle Injection in Non-Linear Diffusive Shock Acceleration with Magnetic Field Amplification
• Origin of very high and ultra high energy cosmic rays