Constraints on the AGN flares as sources of ultra-high energy cosmic rays from the Fermi-LAT observationsстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 10 июня 2020 г.
Аннотация:It is well known that if the most energetic cosmic rays (E>1020 eV) were protons then their acceleration sites should possess some extreme properties, including gigantic luminosity. As no stationary sources with such properties are known in the local (D1020 eV, thus making this scenario feasible, if the UHECR escape spectrum in these sources is rather hard and/or narrow. This shape of spectrum is predicted in a number of present models of strong relativistic collisionless shocks. Also the scenario of acceleration in AGN flares can accommodate constraints coming from the observed arrival distribution of UHECRs. Finally, we demonstrate that in case of heavier UHECR composition all the constraints are greatly relaxed.