Abstract
Recent observations of high-energy cosmic ray electrons by the Fermi-Large Area Telescope (LAT) and the High Energy Stereoscopic System (HESS) experiments between 20GeV and 5TeV have found that the energy spectrum closely follows a broken power law with a break at around 1TeV. On the other hand, measurements of cosmic ray secondary-to-primary ratios like the boron-to-carbon ratio seem to indicate a possible change in the slope at energies around 100GeVn-1. In this paper, we discuss one possible explanation for the observed break in the electron spectrum and its possible correlation with the flattening in the secondary-to-primary ratios at higher energies. In our model, we assume that cosmic rays after acceleration by supernova remnant shock waves, escape downstream of the shock and remain confined within the remnant until the shock slows down. During this time, the high-energy electrons suffer from radiative energy losses and the cosmic ray nuclei undergo nuclear fragmentations due to their interactions with the matter. Once the cosmic rays are released from the supernova remnants, they follow diffusive propagation in the Galaxy where they further suffer from radiative or fragmentation losses.
Original language | British English |
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Pages (from-to) | 1432-1438 |
Number of pages | 7 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 414 |
Issue number | 2 |
DOIs | |
State | Published - Jun 2011 |
Keywords
- Cosmic rays
- ISM: supernova remnants