July 29, 2015 to August 6, 2015
World Forum
Europe/Amsterdam timezone

Ultra-High-Energy Cosmic-Ray Hotspot Observed with the Telescope Array Surface Detectors

Jul 30, 2015, 3:00 PM
World Forum Theater (World Forum)

World Forum Theater

World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Oral contribution CR-EX Parallel CR03 Aniso


Kazumasa Kawata (ICRR, University of Tokyo)


The Telescope Array Experiment has observed a cluster of ultrahigh energy cosmic rays, $E>57$ EeV, called the Hotspot. This was reported in (Abbasi et al., ApJ, 790, L21 (2014)), and was centered in Ursa Major. Using the first five years of data collected by the TA surface detector, the chance probability of this hotspot in an isotropic cosmic-ray sky was calculated to be 3.4$\sigma$. In this work, we update this result using the latest data collected by the TA surface detector. We also discuss possible origins of the hotspot
Collaboration Telescope Array
Registration number following "ICRC2015-I/" 0107

Primary author

Kazumasa Kawata (ICRR, University of Tokyo)


Akimichi Taketa (ERI, University of Tokyo) Benjamin Stokes (University of Utah) Daisuke Ikeda (ICRR, University of Tokyo) Dmitri Ivanov (University of Utah) Eiji Kido (ICRR, University of Tokyo) Gordon Thomson (University of Utah) Grigory Rubtsov (INR RAS) Hiroyuki Sagawa (ICRR, University of Tokyo) Hisao Tokuno (ICRR, University of Tokyo) Igor Tkachev (INR RAS) John Matthews (University of Utah) Masahiro Takeda (ICRR, University of Tokyo) Masaki Fukushima (ICRR, University of Tokyo) Nobuyuki Sakurai (Nagoya University) Peter Tinyakov (Universite Libre de Bruxelles (ULB)) Ryuji Takeishi (ICRR, University of Tokyo) Shigehiro NAGATAKI (Yukawa Institute for Theoretical Physics, Kyoto University) Takeshi Okuda (Ritsumeikan University) Toshiyuki Nonaka (ICRR, University of Tokyo)

Presentation materials