The Cosmic-Ray Spectra: News on their Knees

Abstract

In a comprehensive model of Cosmic Rays (CRs) proposed a decade ago, the energies of the spectral "knees" of the various CR species were predicted to be proportional to mass, rather than charge. The model also predicts the knees to occur at an energy of two to four million times the particle's rest mass. Recent data allow one to verify this prediction, particularly for Fe and lighter-nuclei CRs. But the most stringent test involves the putative knee in the CR electron spectrum, since the mass ratio of electrons to protons (and nuclei) is so very different from their charge ratio(s). Very recent results on the spectra of positrons and electrons at the highest measured energies corroborate the existence of an electron knee, with the expected shape and at the predicted energy.

9 pages, 8 figures. Note added on new CALET data. Published in PLB with cruel and unusual delay

References in corpus (7)

• Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
• Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above $8\times 10^{18}$ eV
• Extended Measurement of the Cosmic-Ray Electron and Positron Spectrum from 11 GeV to 4.8 TeV with the Calorimetric Electron Telescope on the International Space Station
• Polarisation studies of the prompt gamma-ray emission from GRB 041219a using the Spectrometer aboard INTEGRAL
• GRB 140206A: the most distant polarized Gamma-Ray Burst
• A theory of Cosmic Rays
• On the origin of the diffuse gamma-ray background radiation

Cited by in corpus (4)

• A Combined Astrophysical and Dark Matter Interpretation of the IceCube HESE and Throughgoing Muon Events
• Scaling violation in interaction of cosmic ray hadrons and the nature of the 3 PeV knee in the spectrum of primary cosmic rays
• The Maximum Isotropic Equivalent Energy Of Gamma Ray Bursts
• Universal Peaks Ratio In The Spectral Energy Density Of Double Hump Blazars, Gamma Ray Bursts, And Microquasars