Ultra High-Energy Cosmic Ray Observations

Abstract

The year 2007 has furnished us with outstanding results about the origin of the most energetic cosmic rays: a flux suppression as expected from the GZK-effect has been observed in the data of the HiRes and Auger experiments and correlations between the positions of nearby AGN and the arrival directions of trans-GZK events have been observed by the Pierre Auger Observatory. The latter finding marks the beginning of ultra high-energy cosmic ray astronomy and is considered a major breakthrough starting to shed first light onto the sources of the most extreme particles in nature. This report summarizes those observations and includes other major advances of the field, mostly presented at the 30th International Cosmic Ray Conference held in Merida, Mexico, in July 2007. With increasing statistics becoming available from current and even terminated experiments, systematic differences amongst different experiments and techniques can be studied in detail which is hoped to improve our understanding of experimental techniques and their limitations.

9 pages, 8 figures, Invited paper presented at TAUP 2007 (Sendai, Japan), to appear in Journal of Physics

References in corpus (13)

• Correlation of the highest energy cosmic rays with nearby extragalactic objects
• Energy determination in the Akeno Giant Air Shower Array experiment
• Dip in UHECR spectrum as signature of proton interaction with CMB
• Ultra-High Energy Neutrino Fluxes and Their Constraints
• On the transition from Galactic to extragalactic cosmic-rays: spectral and composition features from two opposite scenarios
• New measurement on photon yields from air and the application to the energy estimation of primary cosmic rays
• Search for ultra-high energy photons using air showers
• On the ultra-high energy cosmic ray horizon
• Model Dependence of Lateral Distribution Functions of High Energy Cosmic Ray Air Showers
• Observation of the GZK Cutoff Using the HiRes Detector
• Studies of systematic uncertainties in the estimation of the monocular aperture of the HiRes experiment
• Cosmic Rays from the Knee to the Ankle - Status and Prospects -
• Observations of Ultra-High Energy Cosmic Rays

Cited by in corpus (7)

• Cosmic Rays from the Knee to the Highest Energies
• Analytic calculations of the spectra of ultra-high energy cosmic ray nuclei. I. The case of CMB radiation
• Air Fluorescence Relevant for Cosmic-Ray Detection - Summary of the 5th Fluorescence Workshop, El Escorial 2007
• Cosmic Rays and the Search for a Lorentz Invariance Violation
• Coherent and random UHECR Spectroscopy of Lightest Nuclei along CenA: Shadows on GZK Tau Neutrinos spread in a near sky and time
• Astronomy with ultra high-energy particles
• Ultra-High-Energy Cosmic Rays from a Magnetized Strange Star Central Engine for Gamma-Ray Bursts