Testing the Origin of High-Energy Cosmic Rays
arXiv:1108.1023 · doi:10.1088/0004-637X/752/1/68
Abstract
Recent accurate measurements of cosmic-ray (CR) protons and nuclei by ATIC-2, CREAM, and PAMELA reveal: a) unexpected spectral hardening in the spectra of CR species above a few hundred GeV per nucleon, b) a harder spectrum of He compared to protons, and c) softening of the CR spectra just below the break energy. These newly-discovered features may offer a clue to the origin of the observed high-energy Galactic CRs. We discuss possible interpretations of these spectral features and make predictions for the secondary CR fluxes and secondary to primary ratios, anisotropy of CRs, and diffuse Galactic γ-ray emission in different phenomenological scenarios. Our predictions can be tested by currently running or near-future high-energy astrophysics experiments.
23 pages, 14 color figures. Accepted for publication in ApJ