arXiv 1006.04412010-06-02astro-ph.SR

来自斜磁场Petschek重联的慢激波和传导前沿：双流体效应

Slow shocks and conduction fronts from Petschek reconnection of skewed magnetic fields: two-fluid effects

D. W. Longcope, S. J. Bradshaw

DOI：: 10.1088/0004-637X/718/2/1491

摘要：

在快速磁重联的模型中，磁通转移发生在电流片的一小部分内，触发存储的磁能通过冲击被热化。当初始电流片分离不完全反平行的磁场时，即它们是偏斜的，磁能首先转换为体动能，然后在慢磁声冲击中热化。我们发现，后者类似于平行冲击或流体动力冲击的所有斜角，除了那些非常接近反平行的限制。对于平行激波，重联驱动慢激波的结构最好用离子和电子具有独立温度的双流体方程来研究。这些方程的含时解可用于预测和理解斜磁场重联引起的激波。结果不同于使用单流体模型，如磁流体力学。在双流体模型中，电子被间接加热，因此携带的热通量总是远低于自由流动极限。然而，离子的粘性应力通常接近流体可处理极限。我们发现，对于广泛的斜角和小等离子体β的电子传导前延伸的慢冲击，但仍然在流出射流。在这种情况下，传导在驱动色球蒸发方面所起的作用将比基于单流体反平行模型所预测的更为有限。

英文摘要：

In models of fast magnetic reconnection, flux transfer occurs within a small portion of a current sheet triggering stored magnetic energy to be thermalized by shocks. When the initial current sheet separates magnetic fields which are not perfectly anti-parallel, i.e. they are skewed, magnetic energy is first converted to bulk kinetic energy and then thermalized in slow magnetosonic shocks. We show that the latter resemble parallel shocks or hydrodynamic shocks for all skew angles except those very near the anti-parallel limit. As for parallel shocks, the structures of reconnection-driven slow shocks are best studied using two-fluid equations in which ions and electrons have independent temperature. Time-dependent solutions of these equations can be used to predict and understand the shocks from reconnection of skewed magnetic fields. The results differ from those found using a single-fluid model such as magnetohydrodynamics. In the two-fluid model electrons are heated indirectly and thus carry a heat flux always well below the free-streaming limit. The viscous stress of the ions is, however, typically near the fluid-treatable limit. We find that for a wide range of skew angles and small plasma beta an electron conduction front extends ahead of the slow shock but remains within the outflow jet. In such cases conduction will play a more limited role in driving chromospheric evaporation than has been predicted based on single-fluid, anti-parallel models.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文