Correlation between ultra-high-energy cosmic rays and active galactic nuclei from the fermi large-area telescope

Abstract

We study the possibility that gamma-ray loud active galactic nuclei (AGNs) are the sources of ultrahigh-energy cosmic rays (UHECRs) by using a correlation analysis of their locations and the arrival directions of UHECR. We use data for gamma-ray loud AGN with d a parts per thousand currency sign 100 Mpc from the second Fermi Large-area Telescope AGN catalog and UHECR data with E a parts per thousand yen 55 EeV observed by the Pierre Auger Observatory. The distribution of arrival directions expected from the gamma-ray loud AGN is compared with that of the observed UHECR by using the correlational angular distance distribution and the Kolmogorov-Smirnov test. We conclude that the hypothesis that the gamma-ray loud AGN are the dominant sources of UHECR is disfavored unless there is a large smearing effect due to intergalactic magnetic fields.