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arXiv · 0706.2864

Astrophysical interpretation of the medium scale clustering in the ultra-high energy sky

A. Cuoco·G. Miele·P. D. Serpico
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Abstract

We compare the clustering properties of the combined dataset of ultra-high energy cosmic rays events, reported by the AGASA, HiRes, Yakutsk and Sugar collaborations, with a catalogue of galaxies of the local universe (redshift z<~0.06). We find that the data reproduce particularly well the clustering properties of the nearby universe within z <~0.02. There is no statistically significant cross-correlation between data and structures, although intriguingly the nominal cross-correlation chance probability drops from ~50% to ~10% using the catalogue with a smaller horizon. Also, we discuss the impact on the robustness of the results of deflections in some galactic magnetic field models used in the literature. These results suggest a relevant role of magnetic fields (possibly extragalactic ones, too) and/or possibly some heavy nuclei fraction in the UHECRs. The importance of a confirmation of these hints by Auger data is emphasized.

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A. Cuoco, G. Miele, P. D. Serpico. 2008-02-13. Astrophysical interpretation of the medium scale clustering in the ultra-high energy sky. https://doi.org/10.1016/j.physletb.2007.12.054

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