Speaker
Olivier Deligny
(CNRS/IN2P3)
Description
Recent KASCADE-Grande and Auger results between $10^{17}~$eV and $5~10^{18}~$eV have revealed complex features in the energy spectrum, be it in the all-particle one or in the composition-sensitive ones. They have also revealed that the mass composition is dominated by iron nuclei around $10^{17}~$eV, and by light and intermediate-nuclei elements above $10^{18}~$eV. In this contribution, we argue that these results can be interpreted in a coherent way as the manifestation of an additional component of a different origin from the one responsible for the bulk of Galactic cosmic rays. This component, sub-dominant below $10^{17}~$eV, appears dominant together with the extragalactic one once the standard Galactic component is extinguished above few $10^{17}~$eV, and is responsible for the ankle feature through its rapid suppression above $10^{18}~$eV. Possible signatures left in the large-scale structure of arrival directions are discussed.
Collaboration | -- not specified -- |
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Registration number following "ICRC2015-I/" | 607 |
Primary authors
Imen Al Samarai
Olivier Deligny
(CNRS/IN2P3)