Science2014-01-01 1:09 AM

In Situ Observations of Interstellar Plasma with Voyager 1 跟随旅行者1号原位观测星际等离子体

Abstract
Launched over 35 years ago, Voyagers 1 and 2 are on an epic journey outward from the Sun to reach the boundary between the solar plasma and the much cooler interstellar medium. The boundary, called the heliopause, is expected to be marked by a large increase in plasma density, from about 0.002 per cubic centimeter (cm−3) in the outer heliosphere, to about 0.1 cm−3 in the interstellar medium. On 9 April 2013, the Voyager 1 plasma wave instrument began detecting locally generated electron plasma oscillations at a frequency of about 2.6 kilohertz. This oscillation frequency corresponds to an electron density of about 0.08 cm−3, very close to the value expected in the interstellar medium. These and other observations provide strong evidence that Voyager 1 has crossed the heliopause into the nearby interstellar plasma. 论文摘要 从35年前发射,旅行者1号和2号正在他们史诗般的旅程中, 它们从太阳向外已经到达了太阳等离子体和冷得多的星际介质之间的边界。 这个边界,被称作太阳驻点,其特点被认为是大量的等离子体密度升高,从外日光层的大约0.002每立方厘米(cm-3)到星际介质的约0.1每立方厘米(cm-3)。 2013年4月9日,旅行者1号的等离子体波仪器开始检测到周围生成的频率约为2.6千赫兹的电子等离子体振荡。 这个振荡频率对应于一个大约0.08每立方厘米(cm-3)的电子密度,非常接近于我们预估的在星际介质应该测得的值。 这些发现和其他一些发现为旅行者1号已经跨越了太阳驻点进入周边的星际介质提供了强有力的证据。

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