An asymmetric solar wind termination shock
An asymmetric solar wind termination shock
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DOI：
10.1038/nature07022
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发表时间：
2008-07
期刊：
影响因子：
64.8
通讯作者：
E. Stone;A. Cummings;F. Mcdonald;B. Heikkila;N. Lal;W. Webber
中科院分区：
文献类型：
--
作者：
E. Stone;A. Cummings;F. Mcdonald;B. Heikkila;N. Lal;W. Webber
旅行者2号在南半球83.7度穿越太阳风终止激波，∼10比旅行者1号在北半球发现的更接近太阳。这种不对称性可能表明来自星际磁场、瞬变激波运动或太阳风动力压力的非对称压力。在这里，我们报告了旅行者2号附近的激波加速的4-5 MeV质子的强度是旅行者1号同时观测到的3倍，这表明在两个地点的激波是不同的。(相关论文报道了在激波中观察到的等离子体、磁场、等离子体波和低能粒子。)旅行者2号没有在激波中发现异常宇宙射线的来源，这表明来源在激波上的其他地方，或者在日鞘中、。银河系宇宙线氦的小强度梯度表明，要么梯度在日鞘中更远，要么局部星际银河系宇宙线强度低于预期。
Voyager 2 crossed the solar wind termination shock at 83.7auin the southern hemisphere, ∼10aucloser to the Sun than found by Voyager 1 in the north,,,. This asymmetry could indicate an asymmetric pressure from an interstellar magnetic field,, from transient-induced shock motion, or from the solar wind dynamic pressure. Here we report that the intensity of 4–5 MeV protons accelerated by the shock near Voyager 2 was three times that observed concurrently by Voyager 1, indicating differences in the shock at the two locations. (Companion papers report on the plasma, magnetic field, plasma-wave and lower energy particle observations at the shock.) Voyager 2 did not find the source of anomalous cosmic rays at the shock, suggesting that the source is elsewhere on the shock,,or in the heliosheath,,,,. The small intensity gradient of Galactic cosmic ray helium indicates that either the gradient is further out in the heliosheath or the local interstellar Galactic cosmic ray intensity is lower than expected.