Hinode Observations of Vector Magnetic Field Change Associated with a Flare on 2006 December 13
Masahito Kubo, Takaaki Yokoyama, Yukio Katsukawa, Bruce W Lites, Saku Tsuneta, Yoshinori Suematsu, Kiyoshi Ichimoto, Toshifumi Shimizu, Shin'ichi Nagata, Theodo… 展开作者
Masahito Kubo, Takaaki Yokoyama, Yukio Katsukawa, Bruce W Lites, Saku Tsuneta, Yoshinori Suematsu, Kiyoshi Ichimoto, Toshifumi Shimizu, Shin'ichi Nagata, Theodore D Tarbell, Richard A Shine, Alan M Title, David Elmore
备注:
6 pages, 4 figures, accepted for publication in PASJ (Hinode Special Issue)
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。
英文摘要:
Continuous observations of a flare productive active region 10930 were successfully carried out with the Solar Optical Telescope onboard the Hinode spacecraft during 2007 December 6 to 19. We focus on the evolution of photospheric magnetic fields in this active region, and magnetic field properties at the site of the X3.4 class flare, using a time series of vector field maps with high spatial resolution. The X3.4 class flare occurred on 2006 December 13 at the apparent collision site between the large, opposite polarity umbrae. Elongated magnetic structures with alternatingly positive and negative polarities resulting from flux emergence appeared one day before the flare in the collision site penumbra. Subsequently, the polarity inversion line at the collision site became very complicated. The number of bright loops in Ca II H increased during the formation of these elongated magnetic structures. The flare ribbons and bright loops evolved along the polarity inversion line and one footpoint of the bright loop was located in a region having a large departure of field azimuth angle with respect to its surroundings. The SOT observations with high spatial resolution and high polarization precision reveal temporal change in fine structure of magnetic fields at the flare site: some parts of the complicated polarity inversion line then disappeared, and in those regions the azimuth angle of photospheric magnetic field changed by about 90 degrees, becoming more spatially uniform within the collision site.
Observations of Solar Doppler Shift Oscillations with the EUV Imaging Spectrometer on Hinode
用太阳和日光层观测站的太阳紫外线辐射光谱仪和横滨的布拉格晶体光谱仪在耀斑温度下形成的离子的发射线中观测到了阻尼多普勒频移振荡。这封信报告了用Hinode卫星上的EUV成像光谱仪观测到的在低得多的温度下形成的日冕发射线中的低振幅阻尼振荡。振荡的振幅约为2 km/s,周期约为35 min。衰减时间显示了与形成发射线最低温度相关的一些证据(Fe XII 195.12埃),表现出约43分钟的衰变时间,而最高形成温度发射线(Fe XV 284.16埃)在两个以上的振荡周期内没有表现出衰减的迹象。这些数据似乎与慢磁声驻波一致,但可能与传导阻尼不一致。
Interaction between a fast rotating sunspot and ephemeral regions as the origin of the major solar event on 2006 December 13
2006年12月13日的主要太阳事件的特征是几乎同时发生的一堆热喷出物,一个巨大的双带耀斑和一个扩展的地球定向日冕物质抛射。我们研究了活动区NOAA AR 10930的磁场和太阳黑子的演化,这是事件的源区,而它从12月10日到12月13日经过太阳盘中心。我们发现,与这次事件有关的活动区的明显变化是磁剪切的发展,短暂区的出现和一个较小的太阳黑子的快速旋转。在活动区的磁中性线附近,快速旋转的黑子与短暂区之间的相互作用触发了持续增亮,最终导致大耀斑。这表明,只有在太阳黑子旋转到200 $^{\circ}$之后,才会发生重大事件。太阳黑子围绕其中心旋转至少240 $^{\circ}$,这是已报道的最大太阳黑子旋转角。
Swift XRT Observations of X-ray Flares in GRB Afterglows
Swift XRT自2004年12月23日以来一直在观测GRB余辉。这些观测中有四分之三是在爆发开始后300 s内开始的,这为观察爆发后最初几个小时内GRB余辉的X射线发射行为提供了前所未有的视角。虽然大多数早期余辉具有平滑下降的光变曲线,但有相当一部分在短时间尺度上具有大的X射线耀斑。我们认为,这些耀斑提供支持的模型与延长中央引擎活动产生后期的内部冲击。