在木星上层大气层中存在超音速流的证据
C Emerich1, L B Jaffel, J T Clarke
1Institut d'Astrophysique Spatiale, CNRS, F-91405 Orsay, France.
概括
木星的上层大气层令人惊地动荡,在日光中表现出超音速的速度. 哈勃太空望远镜的观测揭示了复杂的莱曼α (Ly-alpha) 排放配置文件,表明一个动态的木星环境.
科学领域:
- 行星科学 行星科学
- 大气物理学 大气物理学
- 空间物理 空间物理
背景情况:
- 莱曼α (Ly-alpha) 排放是气体巨星大气条件的关键指标.
- 以前的观测表明木星上层大气层相对稳定.
研究的目的:
- 分析木星的Ly-alpha日光发射的详细结构和变异性.
- 为了研究木星上层大气中发生的动态过程.
主要方法:
- 在哈勃太空望远镜 (HST) 上使用戈达德高分辨率光谱仪 (GHRS).
- 获得了木星Ly-alpha发射线形状的高分辨率光谱.
- 分析了分钟时间尺度上的时间变化.
主要成果:
- 观察到复杂且高度可变的Ly-alpha排放线形状.
- 在低度的Ly-alpha凸起区域检测到重要的结构.
- 这些结构与超声速 (几到几十公里/秒) 相对应.
结论:
- 木星的上层大气层出乎意料地充满活力和风暴.
- 观测到的超音速速度挑战了关于行星大气层的先前假设.
- 木星上层大气表现出类似恒星的大气现象.
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