3D MHD Time-dependent Charge State Ionization and Recombination Modeling of the Bastille Day Coronal Mass Ejection
3D MHD Time-dependent Charge State Ionization and Recombination Modeling of the Bastille Day Coronal Mass Ejection
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DOI：
10.3847/1538-4357/aceef8
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发表时间：
2023-09
期刊：
影响因子：
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通讯作者：
Y. Rivera;J. Raymond;K. Reeves;S. Lepri;R. Lionello;C. Downs;Maurice L. Wilson;Nicolas Trueba-Nicolas-Trueb
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文献类型：
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作者：
Y. Rivera;J. Raymond;K. Reeves;S. Lepri;R. Lionello;C. Downs;Maurice L. Wilson;Nicolas Trueba-Nicolas-Trueb
日冕物质抛射（CME）的重离子特征表明，在爆发和传播的早期阶段发生了快速和强烈的加热。然而，加热的性质，产生高度电离的电荷状态，经常在原位观察到的是不完全约束。MHD模拟的巴士底日CME作为一个试验台，以检查重离子的形成的起源和条件，在CME内演变与在L1的通道期间观察到的连接。特别是，我们调查的双峰性质的Fe电荷态分布，这是一个典型的重离子签名的CME子结构，以及高度电离等离子体的来源。我们发现，所经历的跟踪等离子体结构的离子签名检查的主要加热是由于通过冲击等离子体在CME前端的场对齐的热传导。此外，双峰Fe分布可以通过显著加热和快速冷却的日珥物质产生。然而，虽然实现了显着的加热，在原位观察到的Fe离子的最高电离阶段没有再现。此外，碳和氧的电荷态分布没有得到很好的复制，由于整个喷出物中观察到的异常重离子辍学。总的来说，结果表明，需要额外的电离，以配合观察。电离的一个重要驱动力可能来自超热电子，例如在重联过程中通过费米加速产生的电子，这表明该过程对极端CME爆发的发展和延长加热至关重要，如巴士底日CME。
Heavy ion signatures of coronal mass ejections (CMEs) indicate that rapid and strong heating takes place during the eruption and early stages of propagation. However, the nature of the heating that produces the highly ionized charge states often observed in situ is not fully constrained. An MHD simulation of the Bastille Day CME serves as a test bed to examine the origin and conditions of the formation of heavy ions evolving within the CME in connection with those observed during its passage at L1. In particular, we investigate the bimodal nature of the Fe charge state distribution, which is a quintessential heavy ion signature of CME substructure, as well as the source of the highly ionized plasma. We find that the main heating experienced by the tracked plasma structures linked to the ion signatures examined is due to field-aligned thermal conduction via shocked plasma at the CME front. Moreover, the bimodal Fe distributions can be generated through significant heating and rapid cooling of prominence material. However, although significant heating was achieved, the highest ionization stages of Fe ions observed in situ were not reproduced. In addition, the carbon and oxygen charge state distributions were not well replicated owing to anomalous heavy ion dropouts observed throughout the ejecta. Overall, the results indicate that additional ionization is needed to match observation. An important driver of ionization could come from suprathermal electrons, such as those produced via Fermi acceleration during reconnection, suggesting that the process is critical to the development and extended heating of extreme CME eruptions, like the Bastille Day CME.