我们的目的是确定日冕亮点的等离子体特性,并将其磁图数据外推的磁拓扑结构与其在X射线图像中的外观进行比较。我们分析获得的光谱数据与EIS/Hinode,钙II H和G-波段图像从SOT/Hinode,紫外图像从TRACE,X射线图像从XRT/Hinode和高分辨率/高节奏的磁图数据从MDI/SoHO。BP由几个日冕环组成,如X射线图像所示,而色球结构由数十个小亮点组成,如Ca II H所示。在Ca II BP和磁场增加之间存在良好的相关性,这意味着Ca II H通带是磁通量浓度的良好指标。BP区的多普勒速度在6至15 km/s之间,来自Fe XII和Fe XIII线,而Fe XIV和Si VII的多普勒速度在-15至+15 km/s之间。日冕电子密度为3.7 × 10^9 cm^-3。发现正磁通量与X射线光变曲线之间有很好的相关性。外推的磁场配置与X射线图像中所见的组成BP的一些环之间的显著一致性表明,亮点中的大部分磁场接近电势。正磁通量和X射线辐射之间的密切相关性表明,磁重联释放的能量是由磁通量的出现或消除所激发的。
英文摘要:
Our aim is to determine the plasma properties of a coronal bright point and compare its magnetic topology extrapolated from magnetogram data with its appearance in X-ray images. We analyse spectroscopic data obtained with EIS/Hinode, Ca II H and G-band images from SOT/Hinode, UV images from TRACE, X-ray images from XRT/Hinode and high-resolution/high-cadence magnetogram data from MDI/SoHO. The BP comprises several coronal loops as seen in the X-ray images, while the chromospheric structure consists of tens of small bright points as seen in Ca II H. An excellent correlation exists between the Ca II BPs and increases in the magnetic field, implying that the Ca II H passband is a good indicator for the concentration of magnetic flux. Doppler velocities between 6 and 15 km/s are derived from the Fe XII and Fe XIII lines for the BP region, while for Fe XIV and Si VII they are in the range from -15 to +15 km/s. The coronal electron density is 3.7x10^9 cm^-3. An excellent correlation is found between the positive magnetic flux and the X-ray light-curves. The remarkable agreement between the extrapolated magnetic field configuration and some of the loops composing the BP as seen in the X-ray images suggests that a large fraction of the magnetic field in the bright point is close to potential. The close correlation between the positive magnetic flux and the X-ray emission suggests that energy released by magnetic reconnection is stimulated by flux emergence or cancellation.
从SOHO/EIT Fe XII图像中发现的太阳宁静区的几个日冕亮点被发现有一个从诞生到衰变的时间演化,这是非常好的相关性的磁通量的上升和下降,确定与SOHO/MDI仪器的光球磁图。发现亮点的辐射损耗远小于导电损耗,但两者之和与相关磁场的可用能量相当。在这些亮点的寿命期间发生了几次小的“网络耀斑”,强调了这些事件与磁场的密切联系。
Hinode Observations of Vector Magnetic Field Change Associated with a Flare on 2006 December 13
2007年12月6日至19日期间,利用日出号航天器上的太阳光学望远镜成功地对耀斑活动区10930进行了连续观测。我们专注于光球磁场在这个活动区的演变,和磁场属性在网站的X3.4级耀斑,使用时间序列的矢量场地图具有高空间分辨率。X3.4级耀斑发生在2006年12月13日,在巨大的相反极性的本影之间的明显碰撞地点。在耀斑爆发前一天,在碰撞地点的半影区出现了由磁通量出现引起的正负极性交替的细长磁结构。随后,在碰撞现场的极性反转线变得非常复杂。在这些细长的磁性结构的形成过程中,在Ca II H的明亮的环路的数量增加。耀斑带和亮环沿极性反转线演化,亮环的一个足点位于磁场方位角偏离较大的区域。高空间分辨率和高偏振精度的SOT观测揭示了耀斑区磁场精细结构的时间变化:复杂的极性反转线部分消失,光球磁场方位角变化约90 °,在碰撞区内空间分布更加均匀。