在太阳星际相互作用中的全球日球终结冲击强度
E J Zirnstein1, R Kumar2, B L Shrestha1
1Department of Astrophysical Sciences, Princeton University, Princeton, NJ USA.
概括
天球终结冲击 (HTS) 的强度在全球范围内有所不同. 在太阳最小值期间发生更高的极性压缩,受到太阳风动力学和星际介质相互作用的影响.
科学领域:
- 空间物理 空间物理
- 太空物理学 太空物理学
- 等离子体物理学的物理学
背景情况:
- 日球终结冲击 (HTS) 是一个关键的边界,在太阳风 (SW) 在进入星际介质之前被压缩和加热.
- 全球HTS属性由于局部测量有限,主要是从旅行者航天器仅在两个方向进行的,因此了解得很少.
- HTS加速粒子在日球和星际介质之间的压力平衡中发挥着关键作用.
研究的目的:
- 确定日球终结冲击 (HTS) 的全球性质和强度.
- 调查HTS压缩的变化及其与太阳活动和太阳风条件的关系.
主要方法:
- 利用细胞中的粒子,试验粒子和磁动力学模拟来建模HTS.
- 使用星际边界探测器 (IBEX) 任务的观测数据,特别是能量中性原子的受限模拟结果.
- 分析了能量中性原子数据以推断HTS的强度和特征.
主要成果:
- 揭示了太阳最小值与太阳最大值相比,在极点附近的压缩更高,与更高的马赫数SW流量有关.
- 鉴定了HTS强度的南北不对称性,归因于极地冠状孔的演化.
- 在日球侧面附近观察到的最小压缩,可能是由于太阳风在较长距离上因质量负荷而减速而引起的.
结论:
- 在全球范围内,HTS的强度表现出显著的差异,极地和侧面区域之间存在明显的差异.
- 太阳最小条件导致HTS的极性压缩增强.
- 在HTS强度和太阳风和星际介质的动态之间存在很强的相关性.
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