1112.6388 (Daniele Fargion)
Daniele Fargion
Recent UHECR mass compositions did show a negligible nucleon composition and
an UHECR nuclei (light or heavy) signatures. The absence of UHECR events toward
Virgo cluster, the unique spread clustering of events around Cen-A, our nearest
AGN, suggested a He-like nuclei as the main extragalactic UHECR component from
Cen A, coexisting with Auger and HIRES composition. Because the light nuclei
fragility such He UHECR cannot arrive from Virgo (being too far). Multiplet at
tens EeV along Cen A confirm this interpretation as foreseen fragments (D;He3;
p). However remaining majority of UHECR clustering are partially correlated
with Al26 galactic radioactive MeV map; also a few TeV gamma anisotropy maps
seem to correlate ; rare UHECR triplet are overlapping on Vela TeV anisotropy
and other nearest galactic gamma sources (as partially Crab and Galactic Center
core). Therefore UHECR might be also (or mostly) heavy radioactive galactic
nuclei as Ni56, Ni57 and Co57 bent from the sources whose radioactivity and
decay in flight is boosted (Lorentz factor near a billion) leading to and
tracing TeV correlated sky anisotropy. The UHECR spectra cut maybe not an
extragalactic GZK feature but the imprint of a galactic confinement.
View original:
http://arxiv.org/abs/1112.6388
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