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arXiv 2107.02580astro-ph.SR
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太阳暗条的磁扭曲

Magnetic Twists of Solar Filaments

Jinhan Guo, Yiwei Ni, Ye Qiu, Ze Zhong, Yang Guo, Pengfei Chen

摘要:

太阳暗条是位于磁倾角的冷而致密的物质,与周围的日冕等离子体相比,它显示出独特的辐射特征。它们与日冕剪切和扭曲的磁场线有关。然而,由于缺乏对灯丝内部磁场的常规观测,支撑灯丝材料的确切磁结构不容易确定。由于许多暗条位于弱场区上方,因此几乎不可能通过将传统方法应用于嘈杂的光球磁图,特别是水平分量来推断它们的日冕磁结构。本文用正则化的毕奥-萨伐尔定律构造了某些细丝的磁结构,并计算了它们的磁扭转。此外,我们还对Titov-Demoulin修正模型的磁通绳进行了参数测量,以探讨影响无力磁通量绳扭转的因素。结果表明,无力磁绳的扭转与其轴长与小半径之比成正比,而与上覆背景磁场强度基本无关。因此,我们推断,长的静态灯丝可能是由更多的扭曲磁通绳比短的活跃区灯丝,这是一致的观察。

英文摘要:

Solar filaments are cold and dense materials situated in magnetic dips, which show distinct radiation characteristics compared to the surrounding coronal plasma. They are associated with coronal sheared and twisted magnetic field lines. However, the exact magnetic configuration supporting a filament material is not easy to be ascertained because of the absence of routine observations of the magnetic field inside filaments. Since many filaments lie above weak-field regions, it is nearly impossible to extrapolate their coronal magnetic structures by applying the traditional methods to noisy photospheric magnetograms, in particular the horizontal components. In this paper, we construct magnetic structures for some filaments with the regularized Biot--Savart laws and calculate their magnetic twists. Moreover, we make a parameter survey for the flux ropes of the Titov-Demoulin-modified model to explore the factors affecting the twist of a force-free magnetic flux rope. It is found that the twist of a force-free flux rope is proportional to its axial length to minor radius ratio, and is basically independent of the overlying background magnetic field strength. Thus, we infer that long quiescent filaments are likely to be supported by more twisted flux ropes than short active-region filaments, which is consistent with observations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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