论文标题
太阳耀斑期间风扇结构的空点的成像和光谱研究
Imaging and spectral study on the null point of a fan-spine structure during a solar flare
论文作者
论文摘要
使用多仪器观察，我们对太阳耀斑期间风扇螺旋磁拓扑的空点进行了第一个同时的成像和光谱研究。当磁重新连接发生在零点时，风扇螺旋构型在（极）紫外线通道中亮起。在H $α$图像中，风扇螺旋结构部分由从重新连接位点弹出的双向材料流填充和概述。推断的冠状磁场证实了风扇螺旋拓扑的存在。耀斑峰之前和之后，流出的总速度估计约为60 km s $^{ - 1} $。在耀斑期间，在蓝翼和红翼中，重新连接区域的SI IV线曲线都得到了增强。在耀斑峰值时间，流出的总速度被发现为144 km s $^{ - 1} $。在Si IV配置文件上进行了超级封码，有几个深的吸收线，蓝色几十km s $^{ - 1} $。原因是在Si IV通道中观察到的明亮重新连接区域位于较冷的材料下，在H $α$线中显示为深色特征。蓝光的吸收线表明冷却材料向观察者运动。吸收线的深度也取决于冷却材料的量。这些结果表明，这种光谱曲线可以用作诊断重新连接位点上方较冷材料的性能的工具。
Using the multi-instrument observations, we make the first simultaneous imaging and spectral study on the null point of a fan-spine magnetic topology during a solar flare. When magnetic reconnection occurs at the null point, the fan-spine configuration brightens in the (extreme-)ultraviolet channels. In the H$α$ images, the fan-spine structure is partly filled and outlined by the bi-directional material flows ejected from the reconnection site. The extrapolated coronal magnetic field confirms the existence of the fan-spine topology. Before and after the flare peak, the total velocity of the outflows is estimated to be about 60 km s$^{-1}$. During the flare, the Si IV line profile at the reconnection region is enhanced both in the blue-wing and red-wing. At the flare peak time, the total velocity of the outflows is found to be 144 km s$^{-1}$. Superposed on the Si IV profile, there are several deep absorption lines with the blueshift of several tens of km s$^{-1}$. The reason is inferred to be that the bright reconnection region observed in Si IV channel is located under the cooler material appearing as dark features in the H$α$ line. The blueshifted absorption lines indicate the movement of the cooler material toward the observer. The depth of the absorption lines also depends on the amount of cooler material. These results imply that this kind of spectral profiles can be used as a tool to diagnose the properties of cooler material above reconnection site.
