The Most Likely Sources of High-Energy Cosmic-Ray Electrons in Supernova Remnants
The Most Likely Sources of High-Energy Cosmic-Ray Electrons in Supernova Remnants
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DOI：
10.1086/380431
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发表时间：
2003-08
期刊：
影响因子：
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通讯作者：
Ta. Kobayashi;Y. Komori;K. Yoshida;J. Nishimura
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文献类型：
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作者：
Ta. Kobayashi;Y. Komori;K. Yoshida;J. Nishimura
来自超新星遗迹 (SNR) 的非热 X 射线发射和 TeV 伽马射线的证据强化了原始银河宇宙射线电子在 SNR 中加速的假设。高能电子在银河系中传播期间通过同步加速器和逆康普顿过程损失能量。由于这些辐射损失，从 SNR 释放的 TeV 电子在距离大于 ~1 kpc 或时间早于 ~105 年时无法到达太阳系。我们使用分析方法研究了在太阳系中观测到的宇宙射线电子光谱，并考虑了附近信噪比中可能有助于高能电子通量的几个候选源。我们特别讨论了爆炸后信噪比对释放时间的影响，以及源光谱与简单幂律的偏差。通过计算，我们发现一些附近的源，例如 Vela、Cygnus Loop 或 Monogem，可以在 TeV 电子的能谱中以可识别结构的形式留下独特的特征，并显示出对源的各向异性，具体取决于电子从残余物中释放的时间。这表明，除了提供宇宙射线加速和传播机制的信息外，还可以通过TeV区域的精确电子观测来识别特定的宇宙射线源。
Evidence of nonthermal X-ray emission and TeV gamma rays from supernova remnants (SNRs) have strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High-energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Because of these radiative losses, TeV electrons liberated from SNRs at distances larger than ~1 kpc, or times older than ~105 yr, cannot reach the solar system. We investigated the cosmic-ray electron spectrum observed in the solar system using an analytical method and considered several candidate sources among nearby SNRs that may contribute to the high-energy electron flux. In particular, we discuss the effects for the release time from SNRs after the explosion, as well as the deviation of a source spectrum from a simple power law. From this calculation, we found that some nearby sources, such as Vela, Cygnus Loop, or Monogem, could leave unique signatures in the form of identifiable structure in the energy spectrum of TeV electrons and show anisotropies toward the sources, depending on when the electrons were liberated from the remnant. This suggests that, in addition to providing information on the mechanisms of acceleration and propagation of cosmic rays, specific cosmic-ray sources can be identified through the precise electron observation in the TeV region.