Testing a reported correlation between arrival directions of ultrahigh-energy cosmic rays and a flux pattern from nearby starburst galaxies using Telescope Array data
Abstract
The Pierre Auger Collaboration (Auger) recently reported a correlation between the arrival directions of cosmic rays with energies above 39 EeV and the flux pattern of 23 nearby starburst galaxies (SBGs). In this Letter, we tested the same hypothesis using cosmic rays detected by the Telescope Array experiment (TA) in the 9-year period from May 2008 to May 2017. Unlike the Auger analysis, we did not optimize the parameter values but kept them fixed to the best-fit values found by Auger, namely 9.7% for the anisotropic fraction of cosmic rays assumed to originate from the SBGs in the list and 12.9{\deg} for the angular scale of the correlations. The energy threshold we adopted is 43 EeV, corresponding to 39 EeV in Auger when taking into account the energy-scale difference between two experiments. We find that the TA data is compatible with isotropy to within 1.1{\sigma} and with the Auger result to within 1.4{\sigma}, meaning that it is not capable to discriminate between these two hypotheses.
Keywords
Cite
@article{arxiv.1809.01573,
title = {Testing a reported correlation between arrival directions of ultrahigh-energy cosmic rays and a flux pattern from nearby starburst galaxies using Telescope Array data},
author = {Telescope Array Collaboration and R. U. Abbasi and M. Abe and T. Abu-Zayyad and M. Allen and R. Azuma and E. Barcikowski and J. W. Belz and D. R. Bergman and S. A. Blake and R. Cady and B. G. Cheon and J. Chiba and M. Chikawa and A. di Matteo and T. Fujii and K. Fujita and M. Fukushima and G. Furlich and T. Goto and W. Hanlon and M. Hayashi and Y. Hayashi and N. Hayashida and K. Hibino and K. Honda and D. Ikeda and N. Inoue and T. Ishii and R. Ishimori and H. Ito and D. Ivanov and H. M. Jeong and S. Jeong and C. C. H. Jui and K. Kadota and F. Kakimoto and O. Kalashev and K. Kasahara and H. Kawai and S. Kawakami and S. Kawana and K. Kawata and E. Kido and H. B. Kim and J. H. Kim and J. H. Kim and S. Kishigami and S. Kitamura and Y. Kitamura and V. Kuzmin and M. Kuznetsov and Y. J. Kwon and K. H. Lee and B. Lubsandorzhiev and J. P. Lundquist and K. Machida and K. Martens and T. Matsuyama and J. N. Matthews and R. Mayta and M. Minamino and K. Mukai and I. Myers and K. Nagasawa and S. Nagataki and R. Nakamura and T. Nakamura and T. Nonaka and H. Oda and S. Ogio and J. Ogura and M. Ohnishi and H. Ohoka and T. Okuda and Y. Omura and M. Ono and R. Onogi and A. Oshima and S. Ozawa and I. H. Park and M. S. Pshirkov and J. Remington and D. C. Rodriguez and G. Rubtsov and D. Ryu and H. Sagawa and R. Sahara and K. Saito and Y. Saito and N. Sakaki and N. Sakurai and L. M. Scott and T. Seki and K. Sekino and P. D. Shah and F. Shibata and T. Shibata and H. Shimodaira and B. K. Shin and H. S. Shin and J. D. Smith and P. Sokolsky and B. T. Stokes and S. R. Stratton and T. A. Stroman and T. Suzawa and Y. Takagi and Y. Takahashi and M. Takamura and M. Takeda and R. Takeishi and A. Taketa and M. Takita and Y. Tameda and H. Tanaka and K. Tanaka and M. Tanaka and S. B. Thomas and G. B. Thomson and P. Tinyakov and I. Tkachev and H. Tokuno and T. Tomida and S. Troitsky and Y. Tsunesada and K. Tsutsumi and Y. Uchihori and S. Udo and F. Urban and T. Wong and M. Yamamoto and R. Yamane and H. Yamaoka and K. Yamazaki and J. Yang and K. Yashiro and Y. Yoneda and S. Yoshida and H. Yoshii and Y. Zhezher and Z. Zundel},
journal= {arXiv preprint arXiv:1809.01573},
year = {2018}
}
Comments
More accurate title, fixed an inconsistency in the declination range used, with a few figures slightly changing as a result, other minor revisions