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arXiv · 1705.05027

Ultrahigh-energy Cosmic-ray Nuclei from Black Hole Jets: Recycling Galactic Cosmic Rays through Shear Acceleration

Shigeo S. Kimura·Kohta Murase·B. Theodore Zhang
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Abstract

We perform Monte Carlo simulations of transrelativistic shear acceleration dedicated to a jet-cocoon system of active galactic nuclei. A certain fraction of galactic cosmic rays in a halo is entrained, and sufficiently high-energy particles can be injected to the reacceleration process and further accelerated up to 100 EeV. We show that the shear reacceleration mechanism leads to a hard spectrum of escaping cosmic rays, $dL_E/dE\propto E^{-1}-E^0$, distinct from a conventional $E^{-2}$ spectrum. The supersolar abundance of ultrahigh-energy nuclei is achieved due to injections at TeV-PeV energies. As a result, we find that the highest-energy spectrum and mass composition can be reasonably explained by our model without contradictions with the anisotropy data.

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Shigeo S. Kimura, Kohta Murase, B. Theodore Zhang. 2017-05-14. Ultrahigh-energy Cosmic-ray Nuclei from Black Hole Jets: Recycling Galactic Cosmic Rays through Shear Acceleration. https://doi.org/10.1103/physrevd.97.023026

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