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arXiv 1205.3733astro-ph.SR
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由太阳动力学观测站上的大气成像装置观测到的极端紫外波的波动性质的证据

Evidence for the Wave Nature of an Extreme Ultraviolet Wave Observed by the Atmospheric Imaging Assembly Onboard the Solar Dynamics Observatory

Yuandeng Shen, Yu Liu

摘要:

极紫外(EUV)波已经被发现了大约15年。然而,关于它们的物理性质和起源仍然存在重大争议。在本文中,我们报告了一个伴随着X1.9耀斑和部分晕日冕物质抛射的极紫外波。利用高时间和空间分辨率的观测所采取的{ \em太阳动力学天文台}和日地关系天文台,我们能够调查的详细运动学的EUV波。我们发现了几个支持快模波的论点:(1)EUV波的速度(570 km/s)高于宁静日冕的声速。(2)发现EUV波在其传播期间显著减速(-130 m/s2)。(3)极紫外波在其传播路径上产生了环和暗条的振荡,并探测到极冕洞的反射波。(4)当极紫外光波通过两个日冕亮点时,观测到折射或反射效应。(5)当波前开始变得漫反射时,波前后面的变暗区域停止扩展。(6)波前的轮廓表现出色散的性质,和磁声马赫数的EUV波从最高强度跳导出约为1.4。另外,三角测量表明EUV波在光球上方约60-100 μ m的高度范围内传播。我们认为,观测到的极紫外波应该是一个非线性快模磁声波,在日冕中自由传播后,它是由CME扩张的侧翼在初始阶段驱动。

英文摘要:

Extreme Ultraviolet (EUV) waves have been found for about 15 years. However, significant controversy remains over their physical natures and origins. In this paper, we report an EUV wave that was accompanied by an X1.9 flare and a partial halo coronal mass ejection. Using high temporal and spatial resolution observations taken by the {\em Solar Dynamics Observatory} and the Solar-TErrestrial RElations Observatory, we are able to investigate the detailed kinematics of the EUV wave. We find several arguments that support the fast-mode wave scenario: (1) The speed of the EUV wave (570 km/s) is higher than the sound speed of quiet-Sun corona. (2) Significant deceleration of the EUV wave (-130 m/s2) is found during its propagation. (3) The EUV wave resulted in the oscillations of a loop and a filament along its propagation path, and a reflected wave from the polar coronal hole is also detected. (4) Refraction or reflection effect is observed when the EUV wave was passing through two coronal bright points. (5) The dimming region behind the wavefront stopped to expand when the wavefront started to become diffuse. (6) The profiles of the wavefront exhibited a dispersive nature, and the magnetosonic Mach number of the EUV wave derived from the highest intensity jump is about 1.4. In addition, triangulation indicates that the EUV wave propagated within a height range of about 60-100 Mm above the photosphere. We propose that the EUV wave observed should be a nonlinear fast-mode magnetosonic wave that propagated freely in the corona after it was driven by the CME expanding flanks during the initial period.

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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