KINEMATICS AND FINE STRUCTURE OF AN UNWINDING POLAR JET OBSERVED BY THE SOLAR DYNAMIC OBSERVATORY/ATMOSPHERIC IMAGING ASSEMBLY
KINEMATICS AND FINE STRUCTURE OF AN UNWINDING POLAR JET OBSERVED BY THE SOLAR DYNAMIC OBSERVATORY/ATMOSPHERIC IMAGING ASSEMBLY
复制标题
DOI：
10.1088/2041-8205/735/2/l43
复制
发表时间：
2011-06
期刊：
影响因子：
--
通讯作者：
Yuandeng Shen;Yu Liu;Jiangtao Su;A. Ibrahim
中科院分区：
文献类型：
--
作者：
Yuandeng Shen;Yu Liu;Jiangtao Su;A. Ibrahim
我们提出了一个观测研究的运动学和精细结构的解绕极喷流，高的时间和空间观测大气成像组件板上的太阳动力学天文台和太阳磁活动研究望远镜。在上升过程中，射流的形状类似于表面具有螺旋结构的圆柱体，而射流的质量主要分布在圆柱体的外壳上。在径向上，射流在其西侧依次扩展，并经历了三个不同的阶段：逐渐扩展阶段，快速扩展阶段和稳定阶段。每个阶段持续约12分钟。喷流展开运动的角速度估计为11.1 × 10−3 rad s−1（周期= 564 s），喷流向外日冕的扭转运动的角速度估计为1.17-2.55转（或2.34-5.1π）。另一方面，通过计算喷流中磁场的方位分量，并将喷流中储存的自由能与喷流的总能量进行比较，我们发现喷流中的非势磁场足以为喷流提供能量。这些新的观测结果有力地支持了喷流是由磁扭曲驱动的假设，磁扭曲存储在小双极的扭曲闭合场中，并通过双极与周围开放场之间的磁重联释放。
We present an observational study of the kinematics and fine structure of an unwinding polar jet, with high temporal and spatial observations taken by the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory and the Solar Magnetic Activity Research Telescope. During the rising period, the shape of the jet resembled a cylinder with helical structures on the surface, while the mass of the jet was mainly distributed on the cylinder's shell. In the radial direction, the jet expanded successively at its western side and underwent three distinct phases: the gradually expanding phase, the fast expanding phase, and the steady phase. Each phase lasted for about 12 minutes. The angular speed of the unwinding motion of the jet and the twist transferred into the outer corona during the eruption are estimated to be 11.1 × 10−3 rad s−1 (period = 564 s) and 1.17–2.55 turns (or 2.34–5.1π), respectively. On the other hand, by calculating the azimuthal component of the magnetic field in the jet and comparing the free energy stored in the non-potential magnetic field with the jet's total energy, we find that the non-potential magnetic field in the jet is enough to supply the energy for the ejection. These new observational results strongly support the scenario that the jets are driven by the magnetic twist, which is stored in the twisted closed field of a small bipole, and released through magnetic reconnection between the bipole and its ambient open field.