IMAP 的预测：揭示太阳磁场在日球层尾部的作用

本文探讨了太阳磁场在日球层中对太阳风等离子体的准直作用。研究通过磁流体动力学模拟发现，在较高能量下，太阳磁场产生的准直效应会显著影响高纬度中性原子的分布，这为即将进行的 IMAP 任务提供了观测预测。

arXiv:2606.26250v3 Announce Type: replace Abstract: The classic paradigm of the heliosphere considered the solar magnetic field as having a passive role in the heliosheath, yet Opher et al. (2015) and Drake et al. (2015) suggested that the solar magnetic field plays an active role by collimating the solar wind plasma. Previous work has suggested that high-latitude lobes observed by IBEX-Hi energetic neutral atom (ENA) maps are solely due to the fast/slow solar wind profile, yet other works have found that the solar magnetic field may play a role in organizing the lobes as well. Here, using an MHD solution with and without the solar magnetic field, we find that the fast/slow wind profile largely dictates the ENA profile up to $\sim$10-18 keV. Beyond this energy, the collimation effects are more prominent and the fast/slow solar wind profile no longer organizes the maps. The collimation creates two high latitude lobes. By 80 keV, the heliosphere with collimation yields an enhancement of ENAs of the high-latitude tail lobes compared to the low-latitude region by a factor of $\gtrsim$ 1.3, whereas the uncollimated heliosphere yields a ratio $<$ 1. Therefore, IMAP should be able to identify whether the solar magnetic field collimates the