论文标题
由耀斑相关射流诱导的冠状环的横向振荡
Transverse oscillation of a coronal loop induced by a flare-related jet
论文作者
论文摘要
在这项工作中，我们报告了我们的多波长观测值，该观测值是长度为350 mm的大型冠状环的横向振荡。振荡是由井喷冠状射流诱导的，冠状射流与2015年10月16日在AR 12434中的圆形色带耀斑（CRF）有关。我们旨在确定冠状环中的物理参数，包括Alfven速度和磁场强度。在太阳能动力学天文台（SDO）上，通过大气成像组件（AIA）在极端脱离（EUV）波长中观察到射流诱导的扭结振荡。板SDO上的Helioseissic和磁成像仪（HMI）观察到了视线磁图。我们沿着循环进行了几个切片，以组装时间距离图，并使用指数衰减的正弦函数来适合衰减的振荡。获得了扭结振荡的初始幅度，周期和阻尼时间。应用扭结模式的冠状地震学用于估计振荡环中的Alfven速度和磁场强度。此外，我们使用通量绳插入方法通过非线性力场（NLFFF）建模测量了环的磁场。振荡在AIA 171和131中最为明显。振荡几乎沿着环相相，峰初始幅度为13.6 mm，这意味着振荡属于快速站立的扭结模式。振荡持续3.5个周期，平均周期为462 s，平均阻尼时间为976 s。 T/P的值在1.5-2.5范围内。基于冠状动脉学，振荡环中的Alfven速度估计为1210 km。使用两种独立的方法来计算环路的磁场强度，分别使用冠状动脉学和21123 g使用NLFFF建模，从而导致30043 g。
In this work, we report our multi-wavelength observations of the transverse oscillation of a large scale coronal loop with a length of 350 Mm. The oscillation was induced by a blowout coronal jet, which was related to a circular ribbon flare (CRF) in AR 12434 on 2015 October 16. We aim to determine the physical parameters in the coronal loop, including the Alfven speed and magnetic field strength. The jet induced kink oscillation was observed in extreme-ultraviolet (EUV) wavelengths by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). Line of sight magnetograms were observed by the Helioseismic and Magnetic Imager (HMI) on board SDO. We took several slices along the loop to assemble time-distance diagrams, and used an exponentially decaying sine function to fit the decaying oscillation. The initial amplitude, period, and damping time of kink oscillation were obtained. Coronal seismology of the kink mode was applied to estimate the Alfven speed and magnetic field strength in the oscillating loop. In addition, we measured the magnetic field of the loop through non-linear force free field (NLFFF) modeling using the flux rope insertion method. The oscillation is most pronounced in AIA 171 and 131. The oscillation is almost in phase along the loop with a peak initial amplitude of 13.6 Mm, meaning that the oscillation belong to the fast standing kink mode. The oscillation lasts for 3.5 cycles with an average period of 462 s and average damping time of 976 s. The values of t/P lie in the range of 1.5-2.5. Based on coronal seismology, the Alfven speed in the oscillating loop is estimated to be 1210 km. Two independent methods are applied to calculate the magnetic field strength of the loop, resulting in 30043 G using the coronal seismology and 21123 G using the NLFFF modeling, respectively.
