Search for the large-scale cosmic-ray anisotropies using the TA and TALE surface detector arrays

¹ Graduate School of Science, Osaka Metropolitan University, Sumiyoshi, Osaka, Japan
² Nambu Yoichiro Institute of Theoretical and Experimental Physics, Osaka Metropolitan University, Sumiyoshi, Osaka, Japan
³ Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba, Japan

^* Corresponding author: toshi@omu.ac.jp

Published online: 28 April 2023

Abstract

Origins of ultra-high-energy cosmic rays (UHECRs) are still largely unknown. In particular, the “2nd knee” around 10¹⁷ eV could be related to a transition of origins from the galactic to extra-galactic sources. In this scenario, one would expect the large-scale anisotropies of UHECRs to change over the 2nd knee region. We search for large-scale anisotropies using data taken from surface detector (SD) arrays of the Telescope Array experiment (TA), the largest cosmic-ray detector in the northern hemisphere, and from its low energy extension, the Telescope Array Low-energy Extension (TALE). In this contribution, we report on preliminary results in the search for the large-scale cosmic-ray anisotropies with 11-years TA SD and two-years TALE SD data.