Simultaneous observations of Jovian quasi-periodic radio emissions by the Galileo and Cassini spacecraft
Simultaneous observations of Jovian quasi-periodic radio emissions by the Galileo and Cassini spacecraft
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DOI：
10.1029/2003ja010263
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发表时间：
2004-06-29
影响因子：
2.8
通讯作者：
Zarka, P
中科院分区：
文献类型：
--
作者：
Hospodarsky, GB;Kurth, WS;Zarka, P
[1] 2000年12月30日卡西尼号重力辅助飞越木星和扩展的伽利略轨道任务提供了一个独特的机会，可以用两艘航天器同时测量许多木星等离子体波和无线电发射。其中一种发射是木星 III 型无线电发射，也称为木星准周期 (QP) 发射。即使两个航天器相距很远并且位于非常不同的本地时间（LT），QP 发射的同时观测也显示出非常相似的特征。这些相似之处表明，这种发射以类似频闪灯的方式（在大角度范围内）发射，而不像许多其他木星无线电发射那样，像随木星磁场旋转的探照灯一样。 QP 爆发的最初来源可能位于木星附近。当发射通过磁层传播时，QP 爆发表现为捕获连续谱的增强。在磁鞘处，较高密度的等离子体分散了爆发的较低频率分量，产生特征性的“类似III型”的光谱形状。
[1] The gravity-assist flyby by Cassini of Jupiter on 30 December 2000 and the extended Galileo orbital mission provided a unique opportunity to obtain simultaneous measurements with two spacecraft of many Jovian plasma wave and radio emissions. One of these emissions is Jovian type III radio emissions, also known as Jovian quasi- periodic (QP) emissions. The simultaneous observations of the QP emissions show very similar characteristics, even when the two spacecraft are separated by large distances and located at very different local times (LT). These similarities suggest that this emission is beamed in a strobe light like manner (over a large angular range) and not like a search light rotating with Jupiter's magnetic field, as many other Jovian radio emissions are. The initial source of the QP bursts is likely located near Jupiter. As the emissions propagate through the magnetosphere, the QP bursts appear as enhancements of the trapped continuum. At the magnetosheath the higher density plasma disperses the lower frequency component of the bursts, producing the characteristic "type III like'' spectral shape.