CHARGE-EXCHANGE COUPLING BETWEEN PICKUP IONS ACROSS THE HELIOPAUSE AND ITS EFFECT ON ENERGETIC NEUTRAL HYDROGEN FLUX
CHARGE-EXCHANGE COUPLING BETWEEN PICKUP IONS ACROSS THE HELIOPAUSE AND ITS EFFECT ON ENERGETIC NEUTRAL HYDROGEN FLUX
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跨越日球顶的拾取离子之间的电荷交换耦合及其对高能中性氢通量的影响
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Desai
中科院分区：
文献类型：
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作者：
E. Zirnstein;J. Heerikhuisen;G. Zank;N. Pogorelov;D. McComas;M. Desai
在太阳风(Sw)和星际局部介质(LISM)之间的相互作用中，拾取离子(PUI)似乎在等离子体的多组分性质中起着不可或缺的作用。对中性粒子和PUI进行动力学处理的三维(3D)MHD模拟目前仍然不可行。根据星际边界探测器最近观测到的高能中性原子(ENA)，本文的目的是利用从3DMHD模拟的SW-LISM与动中性粒子相互作用中提取的PUI性质的估计，来说明由ENA促进的跨越太阳顶层(HP)的PUI之间的复杂耦合。首先，我们改进了Zank等人对内日鞘(IHS)血浆的多组分治疗。包括通过电荷交换灭绝PUI。我们发现，相当数量的能量从热的、终止休克处理的Pui转移到更冷的、“新鲜注入”的Pui群体中。其次，我们扩展了多分量方法来估计外日鞘(OHS)的ENA通量，OHS是由星际氢原子和高能PUI之间的电荷交换形成的。这些PUI是由IHS中的ENA穿过HP并经历电荷交换而形成的。基于对SWISM相互作用的等离子体中性模拟以及对ENAs和PUI的后处理分析，我们的估计表明，在日球层前缘1AU处可见的通量大部分来自∼PUI，介于OHS 0.02到10keV之间，这表明IHS和OHS等离子体之间通过电荷交换进行了强烈的耦合。
Pickup ions (PUIs) appear to play an integral role in the multi-component nature of the plasma in the interaction between the solar wind (SW) and local interstellar medium (LISM). Three-dimensional (3D) MHD simulations with a kinetic treatment for neutrals and PUIs are currently still not viable. In light of recent energetic neutral atom (ENA) observations by the Interstellar Boundary EXplorer, the purpose of this paper is to illustrate the complex coupling between PUIs across the heliopause (HP) as facilitated by ENAs using estimates of PUI properties extracted from a 3D MHD simulation of the SW–LISM interaction with kinetic neutrals. First, we improve upon the multi-component treatment of the inner heliosheath (IHS) plasma from Zank et al. by including the extinction of PUIs through charge-exchange. We find a significant amount of energy is transferred away from hot, termination shock-processed PUIs into a colder, “freshly injected” PUI population. Second, we extend the multi-component approach to estimate ENA flux from the outer heliosheath (OHS), formed from charge-exchange between interstellar hydrogen atoms and energetic PUIs. These PUIs are formed from ENAs in the IHS that crossed the HP and experienced charge-exchange. Our estimates, based on plasma-neutral simulations of the SW–LISM interaction and a post-processing analysis of ENAs and PUIs, suggest the majority of flux visible at 1 AU from the front of the heliosphere, between ∼0.02 and 10 keV, originates from OHS PUIs, indicating strong coupling between the IHS and OHS plasmas through charge-exchange.