论文标题
磁场和能量释放过程的演变在同源爆发耀斑期间
Evolution of magnetic fields and energy release processes during homologous eruptive flares
论文作者
论文摘要
我们探讨了重复堆积和爆炸性磁能的过程，以及磁通绳的形成，最终导致了三种同源的爆发耀斑连续增加强度（即M2.0，M2.6和X1.0）。耀斑起源于2014年3月28日至29日在2014年的NOAA活动区域12017。 EUV的观测和磁化图测量以及冠状磁场建模表明，耀斑是由磁通绳的喷发触发的，该通量绳索由在活性区域的一小部分内嵌入的密集包装的循环系统嵌入。在X射线中，第一个和第二个事件与单个紧凑源的源显示出相似的演化，而第三事件在HXR峰期间，在50-100 KEV处表现出多种发射质心，其中一组强的非热结合源。在大约44小时的时间间隔内的光球磁场涵盖了三种耀斑的出现和取消过程的重要阶段，以及在耀斑区域内的极性反转线附近的显着变化。我们的观察结果将绑扎机制指向爆发的合理触发过程。在第二事件和第三次事件之间，我们观察到了一个突出的磁通阶段，该阶段与活动区域电晕中游离磁能的堆积阶段相关。总之，我们的分析揭示了活动区域中快速发展的光球和冠状磁场之间的有效耦合，这导致了自由能的持续阶段，从而导致了连续增加强度的同源耀斑。
We explore the processes of repetitive build-up and explosive release of magnetic energy together with the formation of magnetic flux ropes that eventually resulted into three homologous eruptive flares of successively increasing intensities (i.e., M2.0, M2.6, and X1.0). The flares originated from NOAA active region 12017 during 2014 March 28-29. EUV observations and magnetogram measurements together with coronal magnetic field modeling suggest that the flares were triggered by the eruption of flux ropes embedded by a densely packed system of loops within a small part of the active region. In X-rays, the first and second events show similar evolution with single, compact sources, while the third event exhibits multiple emission centroids with a set of strong non-thermal conjugate sources at 50-100 keV during the HXR peak. The photospheric magnetic field over an interval of approximately 44 hr encompassing the three flares undergoes important phases of emergence and cancellation processes together with significant changes near the polarity inversion lines within the flaring region. Our observations point toward the tether-cutting mechanism as the plausible triggering process of the eruptions. Between the second and third event, we observe a prominent phase of flux emergence which temporally correlates with the build-up phase of free magnetic energy in the active region corona. In conclusion, our analysis reveals an efficient coupling between the rapidly evolving photospheric and coronal magnetic fields in the active region that led to a continued phase of the build-up of free energy, resulting into the homologous flares of successively increasing intensities.
