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arXiv 2101.09510astro-ph.HE
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探测银河系内部的Cosmic Ray密度

Probing the Cosmic Ray density in the inner Galaxy

Giada Peron, Felix Aharonian, Sabrina Casanova, Ruizhi Yang, Roberta Zanin

摘要:

费米大天区望远镜(LAT)观测到的银河系弥散$γ$射线辐射在距离银河系中心约4千秒差距的区域有一个尖锐的峰值,这可以解释为宇宙射线加速器密度的增强或该区域粒子扩散的改变。对源自分子云的$γ$射线的观测是一种独特的工具,可以用来逐点推断银河系遥远区域的宇宙射线密度。本文分析了位于1.5- 4.5kpc区域的9个分子云方向的11年Fermi-LAT资料。在这些云的位置测量的宇宙射线密度与当地测量的一致。我们表明,宇宙射线密度梯度推断从弥漫的伽马射线发射是宇宙射线加速器的存在,而不是银河系宇宙射线的海洋,由于其传播的全球变化的结果。

英文摘要:

The galactic diffuse $γ$-ray emission, as seen by Fermi Large Area Telescope (LAT), shows a sharp peak in the region around 4 kpc from the Galactic center, which can be interpreted either as due to an enhanced density of cosmic-ray accelerators or to a modification of the particle diffusion in that region. Observations of $γ$-rays originating in molecular clouds are a unique tool to infer the cosmic-ray density point by point, in distant regions of the Galaxy. We report here the analysis of 11 yr Fermi-LAT data, obtained in the direction of nine molecular clouds located in the 1.5--4.5 kpc region. The cosmic-ray density measured at the locations of these clouds is compatible with the locally measured one. We demonstrate that the cosmic-ray density gradient inferred from the diffuse gamma-ray emission is the result of the presence of cosmic-ray accelerators rather than a global change of the sea of Galactic cosmic rays due to their propagation.

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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