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  • Tipo di prodotto / pubblicazione: Articolo scientifico

Uncorrelated Far Active Galactic Nuclei Flaring With
Their Delayed Ultra High Energy Cosmic Rays Events

Daniele Fargion,  Pietro Oliva and Pier Giorgio De Sanctis Lucentini


(Received April 5, 2017)
The most distant Active Galactic Nuclei (AGN), within the allowed Greisen-Zatsepin-Kuzmin (GZK)
cut-off radius (≲ 100 Mpc), have been recently candidate by many authors as the best location for the
observed Ultra High Energy Cosmic Rays (UHECR) origination. Indeed, the apparent homogeneity
and isotropy of recent UHECR signals seems to require a far cosmic isotropic and homogeneous
scenario, involving a proton UHECR courier: our galaxy or nearest local group or super galactic
plane (ruled by the Virgo cluster) are too near and apparently too anisotropic to be in agreement with
the (Pierre Auger Observatory (PAO) and Telescope Array (TA) almost-homogeneous data sample.
However, the few and mild UHECR observed clustering, the so called North and South Hot Spots,
are smeared in wide (18◦) solid angles. Their consequent random walk flight from most far GZK
UHECR sources, nearly at 100 Mpc, must be delayed – with respect to a straight AGN photon gamma
flaring arrival trajectory – at least by a million years. During this time, the AGN jet blazing signal,
its probable axis deflection (such as the helical jet in Mrk 501), its miss alignment or even its almost
certain exhaust activity, may lead to a complete misleading correlation between present UHECR
events and a much earlier active AGN ejection. UHECR maps may be anyway related to galactic
or nearest (Cen A, M82) AGN extragalactic UHECR sources shining in twin Hot Spot. Therefore
we defend our (quite different) scenario where UHECR are mostly made by lightest UHECR nuclei
originated by nearby AGN sources, or few galactic sources, whose delayed signals are reaching us
within few thousand years in the observed smeared sky areas.
KEYWORDS: cosmic rays, UHECRs, AGN, intergalactic magnetic fields