The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and gamma-rays
The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and gamma-rays
复制标题
年轻超新星遗迹中的星际介质：产生宇宙 X 射线和伽马射线的关键
DOI：
10.1007/s10509-021-03960-4
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发表时间：
2021
影响因子：
1.9
通讯作者：
Fukui Yasuo
中科院分区：
文献类型：
--
作者：
Sano Hidetoshi;Fukui Yasuo
本文综述了∼年龄段为2000年的年轻超新星遗迹中高能辐射与星际介质关系的研究进展，重点讨论了RX、J1713.7、RCW3946和−-86。这两个SNR都发射出强烈的非热X射线和TeV射线，它们含有成团分布的星际气体，其中既有原子氢气，也有分子氢气体。我们发现激波-云相互作用为X射线和ISM之间的空间关联提供了一个可行的解释。在这些相互作用中，超新星激波撞击了典型的PC级致密核心，产生了高度湍流的速度场，将磁场放大到0.1-1毫克。这种放大导致了团块周围非热同步辐射的增强，而宇宙射线电子不会穿透这些团块。相应地，非热X射线在PC尺度上表现出与ISM相似的空间分布，而在亚PC尺度上则是反相关的。这些结果预测，强子射线可以从致密的核心发出，从而导致强子射线与ISM之间的空间对应。目前的PC尺度的射线观测分辨率太低，无法解决这种对应关系。使用切伦科夫望远镜阵列进行的未来射线观测将能够解决亚PC尺度的射线分布，并为这些宇宙射线的起源提供线索。
We review recent progress in elucidating the relationship between high-energy radiation and the interstellar medium (ISM) in young supernova remnants (SNRs) with ages of ∼2000 yr, focusing in particular on RX J1713.7−3946 and RCW 86. Both SNRs emit strong nonthermal X-rays and TeV-rays, and they contain clumpy distributions of interstellar gas that includes both atomic and molecular hydrogen. We find that shock–cloud interactions provide a viable explanation for the spatial correlation between the X-rays and ISM. In these interactions, the supernova shocks hit the typically pc-scale dense cores, generating a highly turbulent velocity field that amplifies the magnetic field up to 0.1–1 mG. This amplification leads to enhanced nonthermal synchrotron emission around the clumps, whereas the cosmic-ray electrons do not penetrate the clumps. Accordingly, the nonthermal X-rays exhibit a spatial distribution similar to that of the ISM on the pc scale, while they are anticorrelated at sub-pc scales. These results predict that hadronic-rays can be emitted from the dense cores, resulting in a spatial correspondence between the-rays and the ISM. The current pc-scale resolution of-ray observations is too low to resolve this correspondence. Future-ray observations with the Cherenkov Telescope Array will be able to resolve the sub-pc-scale-ray distribution and provide clues to the origin of these cosmic-rays.