The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7–3946

Autor: Takanori Yoshikoshi, Yoshihiko Mizumoto, Tsuguya Naito, A. Asahara, Fuyuki Tokanai, Geoffrey V. Bicknell, Masatoshi Ohishi, K. Sakurazawa, Ryoji Enomoto, Shinji Hara, K. Uruma, Ko Okumura, Teruhiko Yoshida, Ryo Suzuki, J. Kushida, Masaki Mori, A. Maeshiro, A. Kawachi, F. Kajino, T. Takano, H. Tsunoo, Toru Tanimori, M. Moriya, Shohei Yanagita, Yasushi Muraki, C. Itoh, H. Muraishi, Kyoshi Nishijima, Yutaka Matsubara, S. Hayashi, S. Kabuki, K. Tsuchiya, Tadashi Kifune, S. Maeda, Hidetoshi Kubo, T. Nakase, Jun Kataoka, T. Hara, Shuichi Gunji, A. Watanabe, D. L. Swaby, J. R. Patterson, P. G. Edwards, Hideaki Katagiri, K. Takano
Rok vydání: 2002
Předmět:
Zdroj: Nature. 416:823-826
ISSN: 1476-4687
0028-0836
DOI: 10.1038/416823a
Popis: Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.
Databáze: OpenAIRE