Anisotropies in the Arrival Direction Distribution of Ultra-High Energy Cosmic Rays Measured by the Telescope Array Surface Detector

Abstract

Ultra-high energy cosmic rays (UHECRs) are extremely energetic, charged particles with energies greater than 1018 eV, originating from outer space. We investigate anisotropic patterns in the arrival direction distribution of UHECRs to identify their source locations. The Telescope Array (TA) experiment, the largest UHECR observatory in the northern hemisphere, has observed evidence of two intermediate-scale anisotropies in UHECR arrival direction distributions: the TA Hotspot and the Perseus-Pisces supercluster excess. In this presentation, we will describe an oversampling analysis that we performed to find the excess of events using the data measured by the TA surface detector array. We will report the latest results of the TA Hotspot and Perseus-Pisces supercluster excesses. © Copyright owned by the author(s) under the terms of the Creative Commons.