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arXiv 1405.3262astro-ph.HEastro-ph.GAhep-ph
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星系合并是宇宙射线、中微子和伽马射线的来源

Galaxy Mergers as a Source of Cosmic Rays, Neutrinos, and Gamma Rays

Kazumi Kashiyama, Peter Mészáros

摘要:

我们研究了大质量星系合并或碰撞中粒子的激波加速,发现宇宙射线(CR)可以被加速到第二膝能~0.1-1 EeV甚至更高,其硬谱指数为Gamma ~ 2.这样的CR在合并冲击的动力学时间尺度内通过强子核相互作用失去能量,产生伽马射线和中微子作为副产品。如果约10%的激波耗散能量进入CR加速,一些局部合并星系将产生CTA可探测到的伽马射线对应物。此外,基于和谐宇宙学,其中很大一部分大质量星系在宇宙学时间尺度内经历了重大合并,中微子对应物可以构成冰立方探测到的各向同性背景的约20- 60%。

英文摘要:

We investigate the shock acceleration of particles in massive galaxy mergers or collisions, and show that cosmic rays (CRs) can be accelerated up to the second knee energy ~0.1-1 EeV and possibly beyond, with a hard spectral index Gamma ~ 2. Such CRs lose their energy via hadronuclear interactions within a dynamical timescale of the merger shock, producing gamma rays and neutrinos as a by-product. If ~ 10 % of the shock dissipated energy goes into CR acceleration, some local merging galaxies will produce gamma-ray counterparts detectable by CTA. Also, based on the concordance cosmology, where a good fraction of the massive galaxies experience a major merger in a cosmological timescale, the neutrino counterparts can constitute ~ 20-60 % of the isotropic background detected by IceCube.

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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