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arXiv · 1810.02284

Prospects of detecting a large-scale anisotropy of ultra-high-energy cosmic rays from a nearby source with the K-EUSO orbital telescope

O. Kalashev·M. Pshirkov·M. Zotov
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Abstract

KLYPVE-EUSO (K-EUSO) is a planned orbital detector of ultra-high-energy cosmic rays (UHECRs), which is to be deployed on board the International Space Station. K-EUSO is expected to have a uniform exposure over the celestial sphere and register from 120 to 500 UHECRs at energies above 57 EeV in a 2-year mission. We employed the TransportCR and CRPropa 3 packages to estimate prospects of detecting a large-scale anisotropy of ultra-high-energy cosmic rays from a nearby source with K-EUSO. Nearby active galactic nuclei Centaurus A, M82, NGC 253, M87 and Fornax A were considered as possible sources of UHECRs. A minimal model for extragalactic cosmic rays and neutrinos by Kachelriess, Kalashev, Ostapchenko and Semikoz (2017) was chosen for definiteness. We demonstrate that an observation of $\gtrsim300$ events will allow detecting a large-scale anisotropy with a high confidence level providing the fraction of from-source events is $\simeq$10-15%, depending on a particular source. The threshold fraction decreases with an increasing sample size. We also discuss if an overdensity originating from a nearby source can be observed at around the ankle in case a similar anisotropy is found beyond 57 EeV. The results are generic and hold for other future experiments with a uniform exposure of the celestial sphere.

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O. Kalashev, M. Pshirkov, M. Zotov. 2019-08-15. Prospects of detecting a large-scale anisotropy of ultra-high-energy cosmic rays from a nearby source with the K-EUSO orbital telescope. https://doi.org/10.1088/1475-7516%2F2019%2F09%2F034

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