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arXiv 0911.4482astro-ph.HE
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超新星遗迹中分子云作为Cosmic-Ray加速的探针

Molecular Clouds as a Probe of Cosmic-Ray Acceleration in a Supernova Remnant

Yutaka Fujita, Yutaka Ohira, Shuta J. Tanaka, Fumio Takahara

摘要:

我们研究了超新星遗迹(SNR)中的宇宙射线加速及其逃逸。我们模拟了疏散星团Westerlund 2中隐藏的SNR和老年混合形态SNR W 28的非热粒子和光子谱。我们假设SNR冲击波在低密度空腔中传播,该空腔是通过祖星和/或以前的超新星爆炸的活动产生和加热的。我们指出,宇宙射线的扩散系数周围的SNR是小于1%的远离他们。我们将我们的预测与宇宙射线(费米和H.E.S.S.)照射的分子云的伽马射线谱进行比较。我们发现粒子的光谱指数约为2.3。这可能是因为粒子在Sedov阶段结束时被加速,并且因为粒子的能量依赖性逃逸和传播对光谱没有太大影响。

英文摘要:

We study cosmic-ray acceleration in a supernova remnant (SNR) and the escape from it. We model nonthermal particle and photon spectra for the hidden SNR in the open cluster Westerlund 2, and the old-age mixed-morphology SNR W 28. We assume that the SNR shock propagates in a low-density cavity, which is created and heated through the activities of the progenitor stars and/or previous supernova explosions. We indicate that the diffusion coefficient for cosmic-rays around the SNRs is less than ~1% of that away from them. We compare our predictions with the gamma-ray spectra of molecular clouds illuminated by the cosmic-rays (Fermi and H.E.S.S.). We found that the spectral indices of the particles are ~2.3. This may be because the particles were accelerated at the end of the Sedov phase, and because energy dependent escape and propagation of particles did not much affect the spectrum.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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