Correlation of the UHECR with AGN using the new statistical test methods and the updated data from Pierre Auger Observatory

Abstract

We constructed the statistical test methods to compare the arrival direction of ultra-high energy cosmic rays (UHECR) and distributions of point sources as a candidate for the source of UHECR in our previous work. The main point of our methods is that the two-dimensional distribution of arrival directions is reduced to the one-dimensional distributions, suitable for measuring the correlation with the point sources so that the standard KS test is applied. We used the updated Pierre Auger Observatory (PAO) data as a UHECR data set and the 13th edition of Véron-Cetty and V́eron (VCV) catalog as the AGN data set. Based on the AGN catalog, we have constructed Monte-Carlo simulation under two free parameters; the AGN fraction, f, and the smearing angle, θs. The results of our test excluded the both possibilities that the distribution of UHECR is isotropic and the observed UHECR are completely originated from the selected AGN. However, the appropriate amount of additional isotropic component either through the background contribution or through the large smearing effect makes the correlation relatively high. We hope that the data which are updated by PAO and obtained by Telescope Array experiment will give more evidence for the origin of UHECR.