论文标题

伪流膜对磁通绳演化的影响

Pseudostreamer influence on flux rope evolution

论文作者

Sahade, A., Cécere, M., Sieyra, M. V., Krause, G., Cremades, H., Costa, A.

论文摘要

太阳活动的一个关键方面是喷发与周围的冠状磁场之间的耦合,这决定了喷发事件的轨迹和形态。伪流膜(PSS)是由磁场的弧形形成的冠状磁性结构,该弧形由磁场线盖起来,来自在中央脊柱处相同极性的冠状孔中。它们在脊柱中包含一个磁性零点,可能会影响附近通量绳(FRS)的演变。要了解PS对FR爆发的净效应,首先是研究不同和孤立的FR-PS场景,而这些场景不受其他磁性结构影响。我们进行了数值模拟,其中FR结构位于PS磁构型的附近。 PS的组合磁场和FR导致形成两个磁性空点。我们通过在2.5d中求解磁流体动力方程来发展这种情况。模拟考虑了在引力场和分层气氛的存在下完全电离的可压缩理想等离子体。我们发现,FR的动态行为可以根据FR轨迹及其喷发或限制分为三个不同的类别。我们的分析表明,磁性零点在FR挠度的方向和强度上是决定性的,并且它们的层次结构取决于场景的拓扑布置。此外,PS瓣充当封闭FR的磁笼。我们报告说,笼子的总未签名磁通量是定义FR是否被弹出的关键参数。

A critical aspect of solar activity is the coupling between eruptions and the surrounding coronal magnetic field, which determines the trajectory and morphology of the eruptive event. Pseudostreamers (PSs) are coronal magnetic structures formed by arcs of twin loops capped by magnetic field lines from coronal holes of the same polarity that meet at a central spine. They contain a single magnetic null point in the spine, potentially influencing the evolution of nearby flux ropes (FRs). To understand the net effect of the PS on FR eruptions is first necessary to study diverse and isolated FR-PS scenarios, which are not influenced by other magnetic structures. We performed numerical simulations in which a FR structure is in the vicinity of a PS magnetic configuration. The combined magnetic field of the PS and the FR results in the formation of two magnetic null points. We evolve this scenario by numerically solving the magnetohydrodynamic equations in 2.5D. The simulations consider a fully ionised compressible ideal plasma in the presence of a gravitational field and a stratified atmosphere. We find that the dynamic behaviour of the FR can be categorised into three different classes based on the FR trajectories and whether it is eruptive or confined. Our analysis indicates that the magnetic null points are decisive in the direction and intensity of the FR deflection and their hierarchy depends on the topological arrangement of the scenario. Moreover, the PS lobe acts as a magnetic cage enclosing the FR. We report that the total unsigned magnetic flux of the cage is a key parameter defining whether the FR is ejected or not.

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