宇宙线研究相关的伽马射线天文

Investigating Galactic cosmic rays withγ-ray astronomy

宇宙线是星际介质中最重要的成分之一,然而其起源至今成谜。宇宙线在星际湍动磁场中的扩散在很大程度上抹去了宇宙线加速源的分布信息。而宇宙线扩散过程的能量相关性又改变了宇宙线的初始能谱。因此,伽马射线,作为宇宙线与星际介质中气体和光子相互作用产生的次级产物,能提供更多的关于宇宙线起源的信息。更具体的,与气体分布成协的弥散伽马射线可用来研究宇宙线的分布,而离散的伽马射线源能用来研究单独的宇宙线加速源。本文介绍了该领域的现状和未来前景。

Cosmic rays(CRs)are one of the most important components in the interstellar medium(ISM),and the origin of CRs remains a mystery.The diffusion of CRs in turbulent magnetic fields erases the information on the distribution of CR accelerators to a large extent.The energy dependent diffusion of CRs also significantly modifies the initial(acceleration)spectra of CRs.In this regard,γ-rays,the secondary products of interactions of CRs with gas and photons in the ISM,provide us with more information about the origin of CRs.More specifically,theγ-ray emissions associated with gas,can be used to study the distribution of CRs throughout the Galaxy;discreteγ-ray sources can elucidate the locations of individual CR accelerators.Here,the current status and prospects in these fields are reviewed.