The heliospheric plasma tail under the influence of charge exchange processes with interstellar H atoms
The heliospheric plasma tail under the influence of charge exchange processes with interstellar H atoms
复制标题
星际氢原子电荷交换过程影响下的日光层等离子体尾部
DOI：
10.1023/a:1004953013428
复制
发表时间：
1998
期刊：
影响因子：
2.8
通讯作者：
H. Fahr
中科院分区：
文献类型：
--
作者：
Stefan Jaeger;H. Fahr
太阳系相对于周围星际介质的相对运动形成了一个等离子体界面区域，在那里亚音速星际和太阳风等离子体流适应了一个压力平衡表面，称为日球顶。在这个不连续表面内，太阳等离子体从上风侧偏转到下风侧，最后沿着沿着日球尾部逃离太阳系。由于连续的电荷交换相互作用与星际H原子进入从尾部侧翼的日球顶尾部等离子体，起源于冲击太阳风，改变其热力学性质的冷却和减速，而通过沿着尾巴到更大的下游距离。在这里，我们描述了尾部等离子体的电荷交换诱导的修改，直到最终同化到星际等离子体中。另一方面，中性氢原子是通过日尾中的电荷交换相互作用产生的，这些原子以一定的速度被射回内日球层。我们计算了这些H原子从下风向进入内日球层的速度分布，并研究了它们对下风向H拾取离子产生的贡献。正如我们在本文中所示，总的H-拾取离子的生产率在顺风区占主导地位的反尾H原子的电离在地球轨道内。它们还在1到10 AU之间的距离处主导超过4keV的拾取离子能谱。
The relative motion of the solar system with respect to the ambient interstellar medium is known to form a plasma interface region where the subsonic interstellar and solar wind plasma flows adapt to a pressure equilibrium surface, called the heliopause. Inside this discontinuity surface the solar plasma is deflected from the upwind to the downwind side, finally escaping from the solar system along a heliospheric tail. Due to continuous charge exchange interactions with interstellar H atoms entering from the tailward flanks of the heliopause tail plasma, originating from shocked solar wind, changes its thermodynamic character by cooling and deceleration while passing along the tail to larger downstream distances. Here we describe this charge-exchange-induced modification of the tail plasma up to a final assimilation into the interstellar plasma. On the other hand neutral H atoms are produced by means of charge exchange interactions in the heliotail with velocities by which these atoms are shot back into the inner heliosphere. We calculate the velocity distribution of such H atoms entering the inner heliosphere from the downwind direction and study their contribution to the H-pick-up ion production in the downwind region. As we show in this paper, total H-pick-up ion production rates in the downwind region are dominated by ionization of such anti-tailward H atoms within the orbit of the earth. They also dominate the pick-up ion energy spectrum beyond 4keV at distances between 1 and 10AU.