Speaker
Prof.
Peter Tinyakov
(Universite Libre de Bruxelles)
Description
We search for anisotropy of ultra-high energy cosmic ray (UHECR) events
collected by the Telescope Array detector in the first 3.5 years of operation.
Following earlier studies, we consider the event sets with energy thresholds
of E>10 EeV, E>40 EeV, and E>57 EeV. First, we calculate the autocorrelation
function of the cosmic ray events and find no significant deviations from
isotropy at angular scales from 0 to 40 degres in any of the three sets. Next,
we check the events with E>57 Eev for correlations with nearby active galactic
nuclei and find no significant correlations. Finally, we examine all three
sets for correlations with the large-scale structure of the Universe. We find
that the two higher-energy sets are compatible with both an isotropic
distribution and the hypothesis that UHECR sources follow the matter
distribution of the Universe (the LSS hypothesis), while the event set with
E>10 EeV is compatible with isotropy and not compatible with the LSS
hypothesis at 95% CL at angular scales smaller than ~15 degrees. We also check
whether accounting for the regular Galactic magnetic field can make this set
compatible with the LSS hypothesis.
Primary author
Prof.
Peter Tinyakov
(Universite Libre de Bruxelles)
