he Evidence for the Global Electron Transportation into the Jovian Inner Magnetosphere
he Evidence for the Global Electron Transportation into the Jovian Inner Magnetosphere
复制标题
全球电子传输进入木星内磁层的证据
DOI：
10.1126/science.1256259
复制
发表时间：
2014
期刊：
影响因子：
56.9
通讯作者：
and M. Fujimoto
中科院分区：
文献类型：
--
作者：
K. Yoshioka;G. Murakami;A. Yamazaki;F. Tsuchiya;T. Kimura;M. Kagitani;T. Sakanoi;K. Uemizu;Y. Kasaba;I. Yoshikawa;and M. Fujimoto
木星的磁层是一个强大的粒子加速器，其内部含有极端相对论电子。它们被认为是由外部磁层注入的各向异性热电子(>；10千电子伏特)激发的哨声模波加速的。然而，内部磁层中的电子传输还没有被很好地理解。通过对内磁层极紫外线发射的分析，我们证明了含有热等离子体的通量管的全球向内传输。对内部磁层中的Io等离子体环进行高光谱分辨率扫描观测，使我们能够生成热电子分数的径向轮廓。它随着径向距离的减小而逐渐减小，尽管碰撞时间尺度很短，应该会迅速使它们热化。这表明了快速而持续的热电子补给，这些电子负责激发哨声模波。
Jupiter’s magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.