The Galactic Center: A Petaelectronvolt Cosmic-ray Acceleration Factory
The Galactic Center: A Petaelectronvolt Cosmic-ray Acceleration Factory
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银河中心：千万电子伏宇宙射线加速工厂
DOI：
10.3847/1538-4357/aa5f58
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发表时间：
2016-04
期刊：
影响因子：
--
通讯作者：
Yi-Qing Guo
中科院分区：
文献类型：
--
作者：
Yi-Qing Guo
来自银河系中心（GC）的数太电子伏γ射线在数十太电子伏处有截止，而漫射辐射没有这样的截止，HESS实验认为这是拍电子伏质子加速的指示。重要的是要理解这种不一致性，并研究拍电子伏宇宙射线加速可以解释明显矛盾的点和弥散γ射线谱的可能性。在这项工作中，我们提出宇宙射线在GC中被加速到大于petaelectronvolts。宇宙射线和分子云之间的相互作用是造成今天从点源和漫射源发射出数太电子伏γ射线的原因。由于簇团结构的小体积填充因子（VFF）的增强，γ射线的吸收导致GC中产生数十太电子伏的尖锐截止光谱。远离GC，VFF增长，吸收增强变得可以忽略不计。结果表明，在这种自洽图象下，点源和漫源的γ射线发射谱都能成功地再现。此外，预计点源将在1000 TeV处出现“幸存的尾巴”，这可以通过未来的项目CTA和LHAASO观察到。质子-质子（PP）碰撞过程中同时产生中微子。根据我们的计算，经过5-10年的观测，KM 3 Net实验将能够探测到petaelectronvolt源。
The multiteraelectronvolt γ-rays from the galactic center (GC) have a cutoff at tens of teraelectronvolts, whereas the diffuse emission has no such cutoff, which is regarded as an indication of petaelectronvolt proton acceleration by the HESS experiment. It is important to understand the inconsistency and study the possibility that petaelectronvolt cosmic-ray acceleration could account for the apparently contradictory point and diffuse γ-ray spectra. In this work, we propose that the cosmic rays are accelerated up to greater than petaelectronvolts in the GC. The interaction between cosmic rays and molecular clouds is responsible for the multiteraelectronvolt γ-ray emissions from both the point and diffuse sources today. Enhanced by the small volume filling factor (VFF) of the clumpy structure, the absorption of the γ-rays leads to a sharp cutoff spectrum at tens of teraelectronvolts produced in the GC. Away from the GC, the VFF grows, and the absorption enhancement becomes negligible. As a result, the spectra of γ-ray emissions for both point and diffuse sources can be successfully reproduced under such a self-consistent picture. In addition, a" surviving tail" at∼ 100 TeV is expected from the point source, which can be observed by future projects CTA and LHAASO. Neutrinos are simultaneously produced during proton-proton (PP) collision. With 5–10 years of observations, the KM3Net experiment will be able to detect the petaelectronvolt source according to our calculation.
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DOI：
10.1140/epjc/s10052-017-4635-x
发表时间：
2016-04
期刊：
The European Physical Journal C
影响因子：
--
作者：
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通讯作者：
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DOI：
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发表时间：
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期刊：
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影响因子：
--
作者：
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影响因子：
6.5
作者：
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通讯作者：
Jian-Li Zhang;X. Bi;Hong-Bo Hu
DOI：
10.1088/0004-637x/806/2/159
发表时间：
2014-11
期刊：
The Astrophysical Journal
影响因子：
--
作者：
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通讯作者：
S. Kimura;K. Murase;K. Toma
影响因子：
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