由大质量恒星团驱动的宇宙射线加载的新生外流
A cosmic-ray loaded nascent outflow driven by a massive star cluster
AI总结：
研究大质量恒星团韦斯特伦德1驱动的新生外流，通过伽马射线发射发现相对论电子从银盘出现，其与星团周围辐射偏移但连接平滑，且共同加速粒子能量密度高，暗示宇宙射线加载外流或为年轻大质量恒星团常见特征。
AI中文摘要：
宇宙射线被广泛认为能驱动来自恒星形成星系的外流并深刻影响星系演化，但缺乏宇宙射线携带外流的直接证据。同时，人们越来越意识到大质量恒星团在星系中加速宇宙射线的重要性。本文报告了由大质量恒星团韦斯特伦德1驱动的新生外流的发现。与氢原子中可见空洞重合的千兆电子伏特伽马射线发射追踪了相对论电子从银盘出现的情况。该发射与围绕星团的太电子伏特伽马射线辐射偏移，但在光谱和空间上与之平滑连接。假设标准的非热电子/质子注入效率，共同加速的质子和原子核的隐含能量密度至少比一般星际介质中的高一个数量级。这些粒子因此有可能动态影响外流。这一发现表明，宇宙射线加载的外流可能是年轻大质量恒星团的常见特征，对宇宙射线向银河系晕的传输有影响。
英文摘要：
Cosmic rays are widely held to drive outflows from star-forming galaxies and profoundly influence galaxy evolution. Direct evidence for cosmic-ray carrying outflows is however lacking. At the same time there is increasing awareness of the importance of massive star clusters in the acceleration of cosmic rays in galaxies. Here we report on the discovery of a nascent outflow driven by the massive star cluster Westerlund 1. Giga-electronvolt gamma-ray emission coincident with a cavity visible in atomic hydrogen traces the emergence of a population of relativistic electrons out of the Galactic Disc. The emission is offset from tera-electronvolt gamma-ray radiation surrounding the cluster, but connects to it smoothly spectrally and spatially. The implied energy density of co-accelerated protons and nuclei, assuming standard non-thermal electron/proton injection efficiencies, is at least an order of magnitude higher than that in the general interstellar medium. These particles therefore have the potential to dynamically influence the outflow. This discovery suggests that cosmic-ray loaded outflows may be a common feature of young massive star clusters, with implications for the transport of cosmic rays into the halo of the Galaxy.
