USING CORONAL LOOPS TO RECONSTRUCT THE MAGNETIC FIELD OF AN ACTIVE REGION BEFORE AND AFTER A MAJOR FLARE
USING CORONAL LOOPS TO RECONSTRUCT THE MAGNETIC FIELD OF AN ACTIVE REGION BEFORE AND AFTER A MAJOR FLARE
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DOI：
10.1088/0004-637x/783/2/102
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发表时间：
2013-12
期刊：
影响因子：
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通讯作者：
A. Malanushenko;A. Malanushenko;C. Schrijver;M. DeRosa;M. Wheatland
中科院分区：
文献类型：
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作者：
A. Malanushenko;A. Malanushenko;C. Schrijver;M. DeRosa;M. Wheatland
太阳日冕环的形状对电流的存在很敏感，电流是脉冲活动可用的非势能的载体。我们使用这些信息在一个新的方法建模的日冕磁场的活动区（AR）11158作为一个非线性无力场（NLFFF）。所使用的观测数据是2011年2月15日主要耀斑活动前后的日冕图像，以及地表视线磁场测量结果。这些数据来自太阳动力学天文台上的日震和磁成像仪以及大气成像组件。模型场被约束以尽可能接近冠状环配置，同时也受到无力约束。该方法不使用横向光球磁场分量作为输入，因此不同于基于光球矢量磁图的NLFFF建模方法。我们验证的方法，使用AR 11158的观测在一个时间以及之前的主要耀斑和随后审查的字段演变之前和之后的X2.2耀斑和相关的喷发。模型显示，在不稳定期间释放的能量约为1 × 1032 erg，与驱动如此大的爆发性耀斑所需的能量一致。就在喷发之前，模型场包含一个紧凑的S形束的扭曲通量，这是不存在于喷发后的模型，这是与观测一致的。该模型结构的核心围绕其轴线扭转了10.9整圈。
The shapes of solar coronal loops are sensitive to the presence of electrical currents that are the carriers of the non-potential energy available for impulsive activity. We use this information in a new method for modeling the coronal magnetic field of active region (AR) 11158 as a nonlinear force-free field (NLFFF). The observations used are coronal images around the time of major flare activity on 2011 February 15, together with the surface line-of-sight magnetic field measurements. The data are from the Helioseismic and Magnetic Imager and Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. The model fields are constrained to approximate the coronal loop configurations as closely as possible, while also being subject to the force-free constraints. The method does not use transverse photospheric magnetic field components as input and is thereby distinct from methods for modeling NLFFFs based on photospheric vector magnetograms. We validate the method using observations of AR 11158 at a time well before major flaring and subsequently review the field evolution just prior to and following an X2.2 flare and associated eruption. The models indicate that the energy released during the instability is about 1 × 1032 erg, consistent with what is needed to power such a large eruptive flare. Immediately prior to the eruption, the model field contains a compact sigmoid bundle of twisted flux that is not present in the post-eruption models, which is consistent with the observations. The core of that model structure is twisted by ≈0.9 full turns about its axis.