在日光罩过渡层中,等离子体的向外流速为零
Stamatios M Krimigis1, Edmond C Roelof, Robert B Decker
1Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland 20723, USA. tom.krimigis@jhuapl.edu
Nature
|June 17, 2011
概括
旅行者1号已经进入了日层的零速度等离子层,这表明它接近日. 这一发现挑战了层边界的模型.
科学领域:
- 空间物理 空间物理
- 太空物理学 太空物理学
- 等离子体物理学的物理学
背景情况:
- 旅行者1号在2004年穿越了太阳风终结冲击,进入了日层.
- 太阳层是一个超出终结冲击的能量离子和电子的区域.
- 旅行者1号目前距离终结冲击交叉点大约22AU.
研究的目的:
- 为了确定中等离子体的总体速度.
- 为了调查旅行者1号相对于日间的位置.
- 为了将观察到的等离子流与层的理论模型进行比较.
主要方法:
- 使用能量离子分布异构的测量.
- 分析等离子体在辐射横平面中的散热速度.
- 随着时间的推移,跟踪等离子体速度的辐射成分的变化.
主要成果:
- 血的辐射速度在三年内从~70公里/秒线性下降到~0公里/秒.
- 旅行者1号在过去的八个月里一直停留在一个半径速度为零的区域.
- 这艘航天器似乎已经进入了等离子体流的有限过渡层.
结论:
- 旅行者1号进入了零速度层,这表明它靠近日间断.
- 观察到的流量过渡层与预测尖的日立断层不连续性的模型相矛盾.
- 这一发现为 heliosheath 的结构及其与星际空间的边界提供了新的见解.
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