Cosmic Rays from the Ankle to the Cut-Off

Abstract

Recent advances in measuring and interpreting cosmic rays from the spectral ankle to the highest energies are briefly reviewed. The prime question at the highest energies is about the origin of the flux suppression observed at E ~ 4x10^{19} eV. Is this the long awaited GZK-effect or the exhaustion of sources? The key to answering this question will be provided by the largely unknown mass composition at the highest energies. The high level of isotropy observed even at the highest energies challenges models of a proton dominated composition if extragalactic magnetic fields are on the order of a few nG or less. We shall discuss the experimental and theoretical progress in the field and the prospects for the next decade.

Invited review prepared for Comptes Rendus Physique (2014), in press

References in corpus (8)

• Turbulence and Magnetic Fields in the Large Scale Structure of the Universe
• Teraelectronvolt Astronomy
• Measurement of the proton-air cross-section at $\sqrt{s}=57$ TeV with the Pierre Auger Observatory
• The Cosmic Ray Energy Spectrum Observed with the Surface Detector of the Telescope Array Experiment
• Ankle-like Feature in the Energy Spectrum of Light Elements of Cosmic Rays Observed with KASCADE-Grande
• Search for Correlations between HiRes Stereo Events and Active Galactic Nuclei
• Constraints on the origin of cosmic rays above $10^{18}$ eV from large scale anisotropy searches in data of the Pierre Auger Observatory
• Propagation of UHE Protons through Magnetized Cosmic Web

Cited by in corpus (4)

• Measurement of the cosmic-ray energy spectrum above $2.5\times 10^{18}$ eV using the Pierre Auger Observatory
• Study of Ultra-High Energy Cosmic Ray Composition Using Telescope Array's Middle Drum Detector and Surface Array in Hybrid Mode
• CRPropa 3.2 -- an advanced framework for high-energy particle propagation in extragalactic and galactic spaces
• An Estimate of the Spectral Intensity Expected from the Molecular Bremsstrahlung Radiation in Extensive Air Showers