The mass composition of cosmic rays above 10^17 eV

Abstract

Our knowledge of the mass composition of cosmic rays is deficient at all energies above 10^17. Here systematic differences between different measurements are discussed and, in particular, it is argued that there is no compelling evidence to support the common assumption that vast majority of the cosmic rays of the highest energies are protons. Our knowledge of the mass needs to be improved if we are to resolve uncertainties about the energy spectrum. Improvement is also needed for proper interpretation of data on the arrival direction distribution of cosmic ray.

9 pages, 3 figures. Based on a talk given at XIII ISVHECRI: Pylos, Greece in September 2004

References in corpus (18)

• High Energy Neutrinos from Astrophysical Sources: An Upper Bound
• Detection of a Cosmic Ray with Measured Energy Well Beyond the Expected Spectral Cutoff due to Cosmic Microwave Radiation
• Ultra-high energy cosmic rays without GZK cutoff
• Energy determination in the Akeno Giant Air Shower Array experiment
• Nonthermal Supermassive Dark Matter
• Extremely high energy cosmic rays from relic particle decays
• Tau Neutrinos in the Auger Observatory : A New Window to UHECR Sources
• Measurement of the Cosmic Ray Energy Spectrum and Composition from 10^{17} to 10^{18.3} eV Using a Hybrid Fluorescence Technique
• A Multi-Component Measurement of the Cosmic Ray Composition Between 10^{17} eV and 10^{18} eV
• On the detection of Ultra High Energy Neutrinos with the Auger Observatory
• New constraints from Haverah Park data on the photon and iron fluxes of UHE cosmic rays
• The high energy cosmic ray spectrum from relic particle decay
• Natural Candidates for Superheavy Dark Matter in String and M Theory
• Hybrid simulations of extensive air showers
• The Energy Spectrum of Cosmic Rays Above $3\times 10^{17}$ eV as measured with the Haverah Park Array
• Energy Estimation of UHE Cosmic Rays using the Atmospheric Fluorescence Technique
• A Comparison of Cosmic Ray Composition Measurements at the Highest Energies
• The rate of cosmic ray showers at large zenith angles: a step towards the detection of ultra-high energy neutrinos by the Pierre Auger Observatory

Cited by in corpus (18)

• On astrophysical solution to ultra high energy cosmic rays
• Analytic calculations of the spectra of ultra-high energy cosmic ray nuclei. I. The case of CMB radiation
• The Compton-Getting effect on ultra-high energy cosmic rays of cosmological origin
• Ultrahigh Energy Nuclei Propagation in a Structured, Magnetized Universe
• Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation
• Inductive acceleration of UHECRs in sheared relativistic jets
• Non-Universal Spectra of Ultra-High Energy Cosmic Ray Primaries and Secondaries in a Structured Universe
• Magnetized Sources of Ultra-high Energy Nuclei and Extragalactic Origin of the Ankle
• Clustering properties of ultrahigh energy cosmic rays and the search for their astrophysical sources
• Potential sensitivities to Lorentz violation from nonbirefringent modified Maxwell theory of Auger, HESS, and CTA
• Origin of ultra-high energy cosmic rays in the era of Auger and Telescope Array
• Measurements of the Muon Content of UHECR Air Showers with the Pierre Auger Observatory
• Dip in UHECR and Transition from Galactic to Extragalactic Cosmic Rays
• Anisotropies and clustering of extragalactic cosmic rays
• Observations of Ultra-High Energy Cosmic Rays
• Propagation of Ultra-High Energy Cosmic Rays in Extragalactic Magnetic Fields
• Ultra-high energy cosmic rays: from GeV to ZeV
• High Energy Neutrinos and Cosmic Rays