Galactic modulation of extragalactic cosmic rays: Possible origin of the knee in the cosmic ray spectrum

Abstract

The existence of the spectral break around $\sim 3\times 10^{15}$ eV in the cosmic ray spectrum (referred to as the `knee') is one of the biggest questions in cosmic ray astrophysics. At the same time, the origin of cosmic rays above the knee energies (between 10${}^{15}$ and 10${}^{18}$ eV) is also still unsettled. In this paper, we investigate how the hypothetical extragalactic CRs after modulated by the galactic wind contribute to the knee in the CR spectrum. We numerically calculate the modulated energy spectrum of the hypothetical cosmic rays coming into the galaxy from just outside of the ``galactic sphere'' where the galactic wind terminates. We show that the observed knee structure is reproduced well by a superposition of the modulated component and the galactic cosmic rays originating in supernova remnants.

arXiv commentAccepted for publication in Progress of Theoretical Physics

References in corpus (5)

• Discovery of Non Thermal X-Rays from the Northwest Shell of the New SNR RX J1713.7-3946: The Second SN1006 ?
• Inter-galactic Shock Acceleration and the Cosmic Gamma-ray Background
• A Measurement of the Cosmic Ray Spectrum and Composition at the Knee
• Elemental Composition of Cosmic Rays near the Knee by Multiparameter Measurement of Air Showerss
• The non-thermal radiation - Cluster merger connection

Cited by in corpus (4)

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• Study of Galactic interactions and propagation properties of ultrahigh energy cosmic rays using the precision spectrum from the Pierre Auger Observatory