论文标题
2014年8月24日的圆形耀斑丝带快速降解
Fast degradation of the circular flare ribbon on 2014 August 24
论文作者
论文摘要
太阳耀斑丝带的分离和伸长运动已得到广泛研究。很少探索丝带的降解和消失。在本文中，我们报告了2014年8月24日与两种与两种喷气机（JET1和JET2）相关的C5.5圆形 - 丝带耀斑的多波长观察结果，重点是外圆形色带（CR）的快速降解。耀斑由短的内色带（IR）和外CR组成，是由微射线的喷发触发的。 IR和外部CR的亮度同时以$ \ sim $ 04：58 UT在所有AIA波长中。随后，CR的短距离在1600Å中迅速消失，但在EUV波长中逐渐消失。 CR的长期西部沿逆时针方向退化，并经历了减速。降解明显分为两个阶段：第一阶段的速度更快（58 $ - $ 69 km s $^{ - 1} $）和II期，其明显速度较慢（29 $ - $ 35 km S $^{ - 1} $）。当西方CR完全消失时，第二阶段停在$ \ sim $ 05：10 ut。除了喷气1的向外繁殖外，喷气尖峰在04:55 $ -05：00 UT期间逆时针方向进行了不断的运动。我们得出的结论是，该事件可以通过突破喷气机模型来解释。 IR和Cr的连贯亮度在$ \ sim $ 04：58 UT可能是由于零点附近的冲动交换重新连接而引起的，而西CR的亚alfvénic滑动运动在逆时针方向上表明出现滑动磁性磁性磁性。对连接到西CR的热环的快速消失的另一个可能的解释是，它们是依次重新连接的，而无需在无需之后重新连接后明显滑移。
The separation and elongation motions of solar flare ribbons have extensively been investigated. The degradation and disappearance of ribbons have rarely been explored. In this paper, we report our multiwavelength observations of a C5.5 circular-ribbon flare associated with two jets (jet1 and jet2) on 2014 August 24, focusing on the fast degradation of the outer circular ribbon (CR). The flare, consisting of a short inner ribbon (IR) and outer CR, was triggered by the eruption of a minifilament. The brightness of IR and outer CR reached their maxima simultaneously at $\sim$04:58 UT in all AIA wavelengths. Subsequently, the short eastern part of CR faded out quickly in 1600 Å but gradually in EUV wavelengths. The long western part of CR degraded in the counterclockwise direction and experienced a deceleration. The degradation was distinctly divided into two phases: phase I with faster apparent speeds (58$-$69 km s$^{-1}$) and phase II with slower apparent speeds (29$-$35 km s$^{-1}$). The second phase stopped at $\sim$05:10 UT when the western CR totally disappeared. Besides the outward propagation of jet1, the jet spire experienced untwisting motion in the counterclockwise direction during 04:55$-$05:00 UT. We conclude that the event can be explained by the breakout jet model. The coherent brightenings of the IR and CR at $\sim$04:58 UT may result from the impulsive interchange reconnection near the null point, whereas sub-Alfvénic slipping motion of the western CR in the counterclockwise direction indicates the occurrence of slipping magnetic reconnection. Another possible explanation of the quick disappearance of the hot loops connecting to the western CR is that they are simply reconnected sequentially without the need for significant slippage after the null point reconnection.
