FORCE-FREE FIELD MODELING OF TWIST AND BRAIDING-INDUCED MAGNETIC ENERGY IN AN ACTIVE-REGION CORONA
FORCE-FREE FIELD MODELING OF TWIST AND BRAIDING-INDUCED MAGNETIC ENERGY IN AN ACTIVE-REGION CORONA
复制标题
活动区电晕中扭曲和编织感应磁场的无力场建模
DOI：
10.1088/0004-637x/780/1/102
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Wiegelmann
中科院分区：
文献类型：
--
作者：
Thalmann;Tiwari;Wiegelmann
理论概念，编织磁场线在太阳日冕中可能会消耗足够的能量来解释在活动区（AR）日冕中观察到的增亮现象，直到最近才被高分辨率观测所证实。通过对高分辨率日冕成像仪获得的日冕图像的分析，Cirtain等人报告了磁场线编织的第一个观测证据。（以下简称CG 13）。我们提出了非线性无力重建相关的日冕磁场的基础上太阳动力学天文台/日震和磁成像仪矢量磁图。我们提供与编织冠状结构相关的自由磁能的估计。我们的模型结果表明，编织部位的自由能比CG 13分析估计的自由能多（100倍），加强了AR电晕被场线编织加热的可能性。我们能够适当地评估日冕的自由能，通过使用矢量场测量，我们归因于较低的能量估计CG 13低估（由10倍）的方位场强度。我们还量化了CG 13所指出的与耀斑有关的通量绳的总扭转的增加。从我们的模型中，我们发现通量绳的总扭转在12分钟内增加了约半圈。与另一种方法，我们比较我们的结果，我们评估的磁通绳的组成磁场线的缠绕在彼此之间纯粹基于其建模的冠状三维场线几何形状。据我们所知，这是第一次在这里进行。
The theoretical concept that braided magnetic field lines in the solar corona may dissipate a sufficient amount of energy to account for the brightening observed in the active-region (AR) corona has only recently been substantiated by high-resolution observations. From the analysis of coronal images obtained with the High Resolution Coronal Imager, first observational evidence of the braiding of magnetic field lines was reported by Cirtain et al.(hereafter CG13). We present nonlinear force-free reconstructions of the associated coronal magnetic field based on Solar Dynamics Observatory/Helioseismic and Magnetic Imager vector magnetograms. We deliver estimates of the free magnetic energy associated with a braided coronal structure. Our model results suggest (∼ 100 times) more free energy at the braiding site than analytically estimated by CG13, strengthening the possibility of the AR corona being heated by field line braiding. We were able to appropriately assess the coronal free energy by using vector field measurements and we attribute the lower energy estimate of CG13 to the underestimated (by a factor of 10) azimuthal field strength. We also quantify the increase in the overall twist of a flare-related flux rope that was noted by CG13. From our models we find that the overall twist of the flux rope increased by about half a turn within 12 minutes. Unlike another method to which we compare our results, we evaluate the winding of the flux rope's constituent field lines around each other purely based on their modeled coronal three-dimensional field line geometry. To our knowledge, this is done for the first time here.
DOI：
10.1088/0004-637x/705/1/347
发表时间：
2009
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Berger;M. Asgari
通讯作者：
M. Asgari
DOI：
10.1088/0004-637x/769/1/59
发表时间：
2013-04
期刊：
The Astrophysical Journal
影响因子：
--
作者：
J. Thalmann;S. Tiwari;T. Wiegelmann
通讯作者：
J. Thalmann;S. Tiwari;T. Wiegelmann
基于 SDO/HMI 观测的主要喷发活跃区磁场和能量的演化
DOI：
10.1088/0004-637x/748/2/77
发表时间：
2012
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Hoeksema;Wiegelmann;T.Hayashi;Thalmann
通讯作者：
Thalmann