Speaker
Satyendra Thoudam
(Radboud University)
Description
Motivated by the recent high-precision measurements of the cosmic-ray energy spectrum and composition by several new-generation experiments, a detailed study to understand the observed properties of cosmic rays up to the highest energies is being conducted. The study involves building a cosmic-ray propagation model in the Galaxy that explains the observed spectra of different cosmic-ray elements at GeV-TeV energies measured by balloon and satellite borne experiments. The contribution of Galactic cosmic rays to the all-particle cosmic-ray spectrum at higher energies measured by air-shower experiments is determined by extrapolating the spectra of different elements obtained from the Galactic propagation model to energies above the "knee" ($\sim 3\times 10^{15}$ eV). Only the maximum energy of protons accelerated by the Galactic sources is taken as the model parameter. In addition, the contribution of extra-galactic cosmic rays is calculated by taking a reasonable assumption for the source distribution and the nature of cosmic-ray propagation in the intergalactic magnetic fields. Preliminary results indicate the requirement of an extra component of Galactic cosmic rays in order to explain the observed all-particle energy spectrum between $\sim 10^{16}$ and $10^{18}$ eV. Details about the comparison of the model predictions with the observed all-particle energy spectrum and composition up to energies $\sim 10^{20}$ eV will be presented.
| Registration number following "ICRC2015-I/" | 666 |
|---|---|
| Collaboration | -- not specified -- |
Primary author
Satyendra Thoudam
(Radboud University)
Co-authors
Prof.
Abraham Achterberg
(Radboud University Nijmegen)
Prof.
Heino Falcke
(Radboud University Nijmegen)
Jörg Hörandel
(Ru Nijmegen/Nikhef)
Dr
Jörg Rachen
(Radboud University Nijmegen)
