Testing the Origin of High-energy Cosmic Rays
Abstract
Recent accurate measurements of cosmic-ray (CR) protons and nuclei by ATIC-2, CREAM, and PAMELA reveal (1) unexpected spectral hardening in the spectra of CR species above a few hundred GeV per nucleon, (2) a harder spectrum of He compared to protons, and (3) 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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2012
- DOI:
- 10.1088/0004-637X/752/1/68
- arXiv:
- arXiv:1108.1023
- Bibcode:
- 2012ApJ...752...68V
- Keywords:
-
- astroparticle physics;
- cosmic rays;
- dark matter;
- diffuse radiation;
- diffusion;
- elementary particles;
- gamma rays: ISM;
- infrared: ISM;
- ISM: general;
- radio continuum: ISM;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 23 pages, 14 color figures. Accepted for publication in ApJ
