论文标题
由剪切磁场内的重复形成和当前纸的破坏引起的同源冠状质量弹出
Homologous Coronal Mass Ejections Caused by Recurring Formation and Disruption of Current Sheet within a Sheared Magnetic Arcade
论文作者
论文摘要
太阳通常会从同一源区域反复产生具有相似结构的冠状质量弹出，并且如何开始这些同源喷发仍然是一个空旷的问题。在这里，通过使用新的磁流失动力学模拟，我们表明，可以通过在单个双极构型中连续剪切相同的极性反转线驱动的冠状电流板的重复形成和破坏冠状电流板的破坏来有效地产生同源太阳喷发。这些喷发是通过相同的机制引发的，在这种机制中，内部电流板在逐渐剪切的双极场中缓慢形成，并重新连接当前纸张并驱动喷发。每次爆发都不会释放所有自由能，而是在爆发的通量绳下下方的挡泥板街机中剩下大量。因此，与剪切电场街机相比，通过后挡板街机的进一步剪切可以更容易地形成新的电流纸，这有利于产生下一次喷发。此外，发现新的喷发更强，因为新形成的电流纸具有较大的电流密度和较低的高度。此外，我们的结果还表明存在给定通量分布的磁能阈值，一旦接近此阈值，就会发生喷发。
The Sun often produces coronal mass ejections with similar structure repeatedly from the same source region, and how these homologous eruptions are initiated remains an open question. Here, by using a new magnetohydrodynamic simulation, we show that homologous solar eruptions can be efficiently produced by recurring formation and disruption of coronal current sheet as driven by continuously shearing of the same polarity inversion line within a single bipolar configuration. These eruptions are initiated by the same mechanism, in which an internal current sheet forms slowly in a gradually sheared bipolar field and reconnection of the current sheet triggers and drives the eruption. Each of the eruptions does not release all the free energy but with a large amount left in the post-flare arcade below the erupting flux rope. Thus, a new current sheet can be more easily formed by further shearing of the post-flare arcade than by shearing a potential field arcade, and this is favorable for producing the next eruption. Furthermore, it is found that the new eruption is stronger since the newly formed current sheet has a larger current density and a lower height. In addition, our results also indicate the existence of a magnetic energy threshold for a given flux distribution, and eruption occurs once this threshold is approached.
