The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7–3946
The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7–3946
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DOI：
10.1038/416823a
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发表时间：
2002-04
期刊：
影响因子：
64.8
通讯作者：
R. Enomoto;T. Tanimori;T. Naito;T. Yoshida;S. Yanagita;M. Mori;P. G. Edwards;A. Asahara;G. B
中科院分区：
文献类型：
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作者：
R. Enomoto;T. Tanimori;T. Naito;T. Yoshida;S. Yanagita;M. Mori;P. G. Edwards;A. Asahara;G. B
能量高达~ 1015eV的质子是宇宙射线的主要组成部分，但是关于它们可能被加速到这些能量的具体位置的证据一直缺乏。众所周知，在超新星残骸中，电子可以被加速为宇宙射线能量，当这些残骸撞击周围的星际介质时，与之相关的冲击波也可以提供能量来加速质子。这一过程的特征将是π子（π0）的衰变，π子是质子与星际云中的原子和分子碰撞时产生的：π子衰变产生具有特定光谱能量分布的γ射线。在这里，我们报告了观测到能量为~ 1012eV的γ射线在超新星遗迹RX J1713.7-3946的方向上撞击地球上层大气所产生的光学光子级联阵雨。光谱与介子衰变预测的很好地匹配，不能用其他机制来解释。
Protons with energies up to ∼1015eV 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 (π0), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in γ-rays with a particular spectral-energy distribution,. Here we report the observation of cascade showers of optical photons resulting from γ-rays at energies of ∼1012eV 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.