使用Legolas代码进行流媒体板条本征模分析
Streamer slab eigenmode analysis with the Legolas code
- KU Leuven（荷语天主教鲁汶大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究使用Legolas代码对从数值模拟提取的流媒体板条模型进行本征模分析，识别出匹配观测的快速体扭结模，证实流媒体波是流媒体的本征模。
AI中文摘要：
背景。头盔流媒体是太阳日冕中延伸的大型射线状结构，远离太阳表面时变薄，形成延伸的电流片。这些结构是准稳定的，并观察到支持从太阳向外传播的扭结波，称为头盔流媒体波。目的。有限的分析模型将流媒体波识别为流媒体板条的快速体扭结本征模。为了弥合分析模型与数值模拟之间的差距，我们研究了从模拟中获得的更现实的流媒体板条构型的本征模谱，以检索扭结轮廓并坚定地确立流媒体波是流媒体的本征模。方法。使用从数值模拟中提取的流媒体板条模型，应用Legolas代码计算本征模谱，针对模拟中观察到的波长。在谱中，我们通过比较已建立的Epstein轮廓的分析和数值结果来识别与非线性模拟中行为匹配的模。然后，将识别模的相速度与分析、模拟和观测结果进行比较。结果。对于每种情况，发现谱包含一个匹配流媒体波特性的模。识别模的相速度与观测中测量的相速度兼容，强烈表明观测到的流媒体波是快速体扭结模。由于分析色散关系对内部值的敏感性，与分析板条模型的比较是困难的。
英文摘要：
Context. Helmet streamers are large ray-like structures extending from the solar corona that thin further away from the solar surface, forming an extended current sheet. These structures are quasi-stable, and are observed to support kink waves travelling outward from the Sun, called helmet streamer waves. Aims. Limited analytical models identify streamer waves as fast body kink eigenmodes of the streamer slab. To bridge the gap between analytical models and numerical simulations, we investigate the eigenmode spectrum of more realistic streamer slab configurations, obtained from simulations, to retrieve the kink profiles and firmly establish that streamer waves are eigenmodes of the streamer. Methods. Using a streamer slab model extracted from numerical simulations, the Legolas code is applied to compute the eigenmode spectrum, for wavelengths observed in the simulation. In the spectrum we identify the mode matching the behaviour in the non-linear simulations by comparing to analytical and numerical results for the established Epstein profile. The identified modes's phase speeds are then compared to analytical, simulation, and observational results. Results. For each case, the spectrum is found to contain a mode matching the properties of a streamer wave. The phase speeds of the identified modes are compatible with those measured in observations, strongly suggesting that the observed streamer waves are fast body kink modes. Comparison to the analytical slab model is difficult due to the sensitivity of the analytical dispersion relation to the internal values.
