Radioactivity and fragmentation of UHECR: Correlating gamma anisotropy and neutrino PeV events

TL;DR

This paper explores the complex relationships between ultra-high-energy cosmic rays, gamma-ray anisotropies, and PeV neutrino events, proposing that radioactive nuclei in cosmic sources may explain observed anisotropies and neutrino signals.

Contribution

It introduces a novel hypothesis that radioactive nuclei in cosmic ray sources produce gamma and neutrino signals, linking UHECR spread, gamma anisotropies, and PeV neutrinos.

Findings

Gamma anisotropy may be caused by radioactive nuclei in UHECRs.

PeV neutrino events challenge atmospheric origin explanations.

Radioactive nuclei in GRB-SGR jets could explain observed cosmic phenomena.

Abstract

UHECR (Ultra High Energy Cosmic Rays) were expected to be protons, to fly straight and to suffer from a GZK (opacity on CMB radiation) cut off. AUGER suggested in 2007 that such early UHECR anisotropy was compatible with the foreseen Super-Galactic plane, while both HIRES and AUGER confirmed this apparent GZK cut-off in the spectra. However, the same AUGER composition since 2007 had favored nuclei (and not nucleons). The recent absence of narrow angle clustering in UHECR maps, as it should be expected for protons, the missing of events along the nearest Cluster Virgo, the wide spread (nearly 16 degree angle) of UHECR along Cen A are in disagreement with the first proton-UHECR AUGER understanding. Since 2008 we had claimed a light nuclei role for the Cen A crowded area. However the ICECUBE absence of TeV neutrino clustering or anisotropy, its spectra steepening favors mostly a ruling atmospheric neutrino noise up to tens TeV. However two recent PeV neutrino event, cannot easily coexist or been extrapolated with such an atmospheric ruling scenario, or with GZK (either nucleons or nuclei) secondary expected spectra. Finally tens of TeV gamma anisotropy in ARGO-MILAGRO-ICECUBE maps may hardly be associated with known hadronic sources. We imagine such anisotropy ruled by diffused gamma secondaries, shining along UHECR bending and flight: radioactive (Ni,Co,Al,D, neutron) light and heavy UHECR nuclei in GRB-SGRs-jet, while scattering or decaying in flight, may paint in the sky (by gamma, electrons and neutrinos secondaries) their trajectories and bending, connecting UHECR spread events with TeV anisotropy, and also offering a very realistic source of first, otherwise puzzling, observed PeV neutrinos. Evidences for such relativistic Ni jet in 4U1630-47 system has been observed recently by D\'iaz Trigo collaboration.