Search for EeV protons of galactic origin

Autor: R. Ishimori, R. Zollinger, Kenta Yashiro, Yasunori Saito, Yuichiro Tameda, John N. Matthews, K. Nagasawa, J. Yang, Y. J. Kwon, Eiji Kido, Hideyuki Ohoka, Kazuhiro Machida, J. Lan, S. Kitamura, Masato Takita, M. Abe, Byung Gu Cheon, Hidemi Ito, John Belz, Toshiyuki Nonaka, Elliott Barcikowski, Takayuki Tomida, Igor Tkachev, R. Cady, Motoki Hayashi, J. P. Lundquist, Ryuji Takeishi, BayarJon Paul Lubsandorzhiev, K. Hibino, Ben Stokes, Inkyu Park, T. Matsuyama, L. M. Scott, S. Ozawa, Dmitri Ivanov, Keijiro Mukai, Hiroshi Yamaoka, Tomohiro Matsuda, Mayuko Minamino, K. Honda, Y. Yoneda, N. Inoue, Federico R. Urban, A. Nozato, Y. Hayashi, K. Oki, M. Ohnishi, Yasunori Kitamura, T. Goto, S. Udo, C. C. H. Jui, K. Kawata, M. Allen, Douglas Bergman, Yoshiki Tsunesada, Nobuyuki Sakurai, Masaaki Tanaka, Sergey Troitsky, Daisuke Ikeda, Hideaki Shimodaira, Toru Nakamura, Kenichi Kadota, S. R. Stratton, H. Kawai, K. Kasahara, Akitoshi Oshima, S. B. Thomas, O. Kalashev, Shoichi Kishigami, Koichi Sekino, Kanako Yamazaki, Takahiro Fujii, Tiffany Wong, Priti Shah, K. Saito, Masaki Fukushima, Masaomi Ono, Jyunsei Chiba, Dongsu Ryu, B. K. Shin, Grigory Rubtsov, K. Martens, Hideki Tanaka, S. Yoshida, Y. Takahashi, Mai Takamura, Ryota Onogi, J. H. Kim, Vladim Kuzmin, H. Yoshii, Tareq Abu-Zayyad, A. H. Tirone, R. Yamane, Kiyoshi Tanaka, J. Ogura, Naoto Sakaki, Naoaki Hayashida, Peter Tinyakov, Samuel Blake, Maxim Pshirkov, Shoichi Ogio, T.-A. Shibata, Gordon Thomson, Tom Stroman, Zach Zundel, Pierre Sokolsky, Hang Bae Kim, Akimichi Taketa, Heungsu Shin, Rasha Abbasi, M. Takeda, Fumio Kakimoto, Shigehiro Nagataki, Michiyuki Chikawa, K. Tsutsumi, R. Azuma, S. Kawakami, Hiroyuki Sagawa, Y. Uchihori, T. Suzawa, Isaac Myers, Takaaki Ishii, D. C. Rodriguez, Shingo Kawana, William Hanlon, T. Okuda, H. Tokuno, J. D. Smith, Fumiya Shibata
Rok vydání: 2017
Předmět:
Zdroj: Astroparticle Physics. 86:21-26
ISSN: 0927-6505
Popis: Cosmic rays in the energy range $10^{18.0}$ - $10^{18.5}$ eV are thought to have a light, probably protonic, composition. To study their origin one can search for anisotropy in their arrival directions. Extragalactic cosmic rays should be isotropic, but galactic cosmic rays of this type should be seen mostly along the galactic plane, and there should be a shortage of events coming from directions near the galactic anticenter. This is due to the fact that, under the influence of the galactic magnetic field, the transition from ballistic to diffusive behavior is well advanced, and this qualitative picture persists over the whole energy range. Guided by models of the galactic magnetic field that indicate that the enhancement along the galactic plane should have a standard deviation of about 20$^\circ$ in galactic latitude, and the deficit in the galactic anticenter direction should have a standard deviation of about 50$^\circ$ in galactic longitude, we use the data of the Telescope Array surface detector in $10^{18.0}$ to $10^{18.5}$ eV energy range to search for these effects. The data are isotropic. Neither an enhancement along the galactic plane nor a deficit in the galactic anticenter direction is found. Using these data we place an upper limit on the fraction of EeV cosmic rays of galactic origin at 1.3% at 95% confidence level.
Databáze: OpenAIRE