Observable Signatures of Energy Release in Braided Coronal Loops
Observable Signatures of Energy Release in Braided Coronal Loops
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DOI：
10.3847/1538-4357/aa5ff9
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发表时间：
2017-03
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影响因子：
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通讯作者：
D. Pontin;M. Janvier;S. K. Tiwari;K. Galsgaard;A. Winebarger;J. Cirtain
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文献类型：
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作者：
D. Pontin;M. Janvier;S. K. Tiwari;K. Galsgaard;A. Winebarger;J. Cirtain
我们研究了包含非平凡场线编织的太阳冕环的湍流弛豫。在日冕加热模型中，这种场线在日冕中纠缠的假设由来已久。我们利用MHD模拟和正演模拟工具，重点研究了这种编织磁结构中能量释放的观测特征。其目的是回答以下问题：如果能量释放发生在包含辫状磁通量的日冕环路中，我们应该期待在排放中出现明显可见的特征吗？我们证明，编织磁力线的存在并不能保证观测到的强度出现编织。观察到的强度可能--但不一定--揭示磁场的潜在编织性质，这取决于环内场线纠缠的程度和模式。然而，在所考虑的所有情况下，随着辫子环的松弛，辫子环的演变伴随着局部加热区。讨论了可能影响观测信号的因素。最近来自Hi-C的高分辨率观测声称，首次有直接证据表明日冕中存在辫状磁场。在这里，我们展示了Hi-C数据和我们的一些模拟都在一定范围内给出了编织的外观。
We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such field line tangling in the corona has long been postulated in the context of coronal heating models. We focus on the observational signatures of energy release in such braided magnetic structures using MHD simulations and forward modeling tools. The aim is to answer the following question: if energy release occurs in a coronal loop containing braided magnetic flux, should we expect a clearly observable signature in emissions? We demonstrate that the presence of braided magnetic field lines does not guarantee a braided appearance to the observed intensities. Observed intensities may—but need not necessarily—reveal the underlying braided nature of the magnetic field, depending on the degree and pattern of the field line tangling within the loop. However, in all cases considered, the evolution of the braided loop is accompanied by localized heating regions as the loop relaxes. Factors that may influence the observational signatures are discussed. Recent high-resolution observations from Hi-C have claimed the first direct evidence of braided magnetic fields in the corona. Here we show that both the Hi-C data and some of our simulations give the appearance of braiding at a range of scales.