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Nature25 April 2002

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Nature © Macmillan Publishers Ltd.

Cosmic rays: A supernova pumps up the protons

The electron component of cosmic rays — the stream of high-energy particles that continuously strikes the Earth — is known to come from supernovae. But proving that the energetic protons that form the bulk of cosmic rays arise from the same source has proved difficult. Now, Enomoto et al. have pinpointed these protons to the same 'supernova pumps' that accelerate the electrons to high energies. The high-energy protons, through collisions, create pions that decay to very energetic γ-rays on the way to Earth. These γ-rays give rise to showers of optical photons when they strike Earth's atmosphere from the direction of the supernova remnant RX J1713–713946.

letters to nature
The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946
R. ENOMOTO, T. TANIMORI, T. NAITO, T. YOSHIDA, S. YANAGITA, M. MORI, P. G. EDWARDS, A. ASAHARA, G. V. BICKNELL, S. GUNJI, S. HARA, T. HARA, S. HAYASHI, C. ITOH, S. KABUKI, F. KAJINO, H. KATAGIRI, J. KATAOKA, A. KAWACHI, T. KIFUNE, H. KUBO, J. KUSHIDA, S. MAEDA, A. MAESHIRO, Y. MATSUBARA, Y. MIZUMOTO, M. MORIYA, H. MURAISHI, Y. MURAKI, T. NAKASE, K. NISHIJIMA, M. OHISHI, K. OKUMURA, J. R. PATTERSON, K. SAKURAZAWA, R. SUZUKI, D. L. SWABY, K. TAKANO, T. TAKANO, F. TOKANAI, K. TSUCHIYA, H. TSUNOO, K. URUMA, A. WATANABE & T. YOSHIKOSHI
Nature 416, 823–826 (25 April 2002)
| First Paragraph | Full Text | PDF (280 K) |

news and views
Astronomy: The cosmic accelerator
FELIX AHARONIAN
The cosmic rays that permeate our Galaxy have been attributed to various sources. The discovery of high-energy g-rays from a supernova remnant at last provides concrete evidence for one of the proposed theories.
Nature 416, 797–798 (25 April 2002)
| Full Text | PDF (193 K) |

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