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arXiv · 1506.01196

Cosmic-Ray Hardenings in the Light of AMS-02

Yutaka Ohira·Norita Kawanaka·Kunihito Ioka
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Abstract

Recent precise observations of cosmic rays (CRs) by AMS-02 experiment clearly show (1) harder spectra of helium and carbon compared to protons by $\propto R^{0.08}$, and (2) concave breaks in proton and helium spectra at a rigidity $R \sim 300$ GV. In particular the helium and carbon spectra are exactly similar, pointing to the same acceleration site. We examine possible interpretations of these features and identify a chemically enriched region, that is, superbubbles as the most probable origin of Galactic CRs in high rigidity $R>30$ GV. The similar spectra of CR carbon and helium further suggest that the CRs with $R>30$ GV originate from the supernova ejecta in the superbubble core, mixed with comparable or less amount of interstellar medium. We predict similar spectra for heavy nuclei.

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Yutaka Ohira, Norita Kawanaka, Kunihito Ioka. 2015-06-03. Cosmic-Ray Hardenings in the Light of AMS-02. https://doi.org/10.1103/physrevd.93.083001

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