Past, Present and Future of UHECR Observations

Abstract

Great advances have been made in the study of ultra-high energy cosmic rays (UHECR) in the past two decades. These include the discovery of the spectral cut-off near 5 x 10^19 eV and complex structure at lower energies, as well as increasingly precise information about the composition of cosmic rays as a function of energy. Important improvements in techniques, including extensive surface detector arrays and high resolution air fluorescence detectors, have been instrumental in facilitating this progress. We discuss the status of the field, including the open questions about the nature of spectral structure, systematic issues related to our understanding of composition, and emerging evidence for anisotropy at the highest energies. We review prospects for upgraded and future observatories including Telescope Array, Pierre Auger and JEM-EUSO and other space-based proposals, and discuss promising new technologies based on radio emission from extensive air showers produced by UHECR.

Review paper accepted by Progress of Experimental and Theoretical Physics. 42 pages, 10 figures. Typo corrected

References in corpus (11)

• Indications of Intermediate-Scale Anisotropy of Cosmic Rays with Energy Greater Than 57 EeV in the Northern Sky Measured with the Surface Detector of the Telescope Array Experiment
• Combined fit of spectrum and composition data as measured by 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
• A method for high precision reconstruction of air shower Xmax using two-dimensional radio intensity profiles
• Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum
• Measurement of the Flux of Ultra High Energy Cosmic Rays by the Stereo Technique
• Dust-depletion sequences in damped Lyman-α absorbers: a unified picture from low-metallicity systems to the Galaxy
• The Concepts of "Age" and "Universality" in Cosmic Ray Showers
• Large scale distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory
• Air fluorescence measurements in the spectral range 300-420 nm using a 28.5 GeV electron beam
• Radio Detection of Cosmic Rays -- Achievements and Future Potential

Cited by in corpus (3)

• The Giant Radio Array for Neutrino Detection (GRAND): Science and Design
• Simulations of ultra-high Energy Cosmic Rays in the local Universe and the origin of Cosmic Magnetic Fields
• Early Results from TUS, the First Orbital Detector of Extreme Energy Cosmic Rays