Interchange Slip-Running Reconnection and Sweeping SEP Beams
Interchange Slip-Running Reconnection and Sweeping SEP Beams
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DOI：
10.1007/s11207-011-9886-3
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发表时间：
2011-05
期刊：
影响因子：
2.8
通讯作者：
S. Masson;G. Aulanier;E. Pariat;K. Klein
中科院分区：
文献类型：
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作者：
S. Masson;G. Aulanier;E. Pariat;K. Klein
我们提出了一个新的模型来解释如何粒子（太阳能高能粒子; SEP），加速在重联网站，是不是磁连接到地球上，最终可以传播沿着连接良好的开放通量管。我们的模型是基于低β电阻磁流体动力学模拟的结果的三维线束缚和初始电流自由的双极，这是嵌入在一个非均匀的开放势场。这种构型的拓扑结构是不对称的冠状零点，具有封闭的扇形表面和开放的外脊。当受到缓慢的光球剪切运动的驱动时，最初完全锚定在扇形穹顶下方的磁力线在零点重新连接，并跳到开放的磁畴。这是在2D中绘制和计算的标准互换模式。在3D中的关键结果是，位于外脊附近的重新连接的开放场线保持连续重新连接，跨越开放的准分界线层，如先前确定的非开放零点重新连接。这些磁力线的明显滑动运动导致在高空形成一个延伸的窄磁通量管。由于滑移重联，我们推测，如果高能粒子穿过扩散区或在扩散区内加速，它们将沿着沿着不断重联的场线连续注入，这些场线连接得越来越远离脊。在整个太阳的尺度上，由于3R以下的磁力线超径向膨胀，这种高能粒子可以很容易地以磁力线的形式注入，并在相当长的距离上滑动，最终到达与地球连接良好的遥远的通量管。
We present a new model to explain how particles (solar energetic particles; SEPs), accelerated at a reconnection site that is not magnetically connected to the Earth, could eventually propagate along the well-connected open flux tube. Our model is based on the results of a low-β resistive magnetohydrodynamics simulation of a three-dimensional line-tied and initially current-free bipole, which is embedded in a non-uniform open potential field. The topology of this configuration is that of an asymmetric coronal null point, with a closed fan surface and an open outer spine. When driven by slow photospheric shearing motions, field lines, initially fully anchored below the fan dome, reconnect at the null point, and jump to the open magnetic domain. This is the standard interchange mode as sketched and calculated in 2D. The key result in 3D is that reconnected open field lines located in the vicinity of the outer spine keep reconnecting continuously, across an open quasi-separatrix layer, as previously identified for non-open-null-point reconnection. The apparent slipping motion of these field lines leads to formation of an extended narrow magnetic flux tube at high altitude. Because of the slip-running reconnection, we conjecture that if energetic particles would be traveling through, or be accelerated inside, the diffusion region, they would be successively injected along continuously reconnecting field lines that are connected farther and farther from the spine. At the scale of the full Sun, owing to the super-radial expansion of field lines below 3R⊙, such energetic particles could easily be injected in field lines slipping over significant distances, and could eventually reach the distant flux tube that is well-connected to the Earth.