Waves of Magnetic-field Variations Observed in a Flare-excited Sunquake Event
Waves of Magnetic-field Variations Observed in a Flare-excited Sunquake Event
复制标题
在耀斑激发的日震事件中观察到的磁场变化波
DOI：
10.3847/2041-8213/aacbd6
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Ruizhu Chen
中科院分区：
文献类型：
--
作者：
Junwei Zhao;Ruizhu Chen
我们报告检测磁场变化的波，与耀斑激发的太阳地震波。2017年9月6日发生的一次X-9.3耀斑激发了强烈的日震，观测到日震波扫过耀斑的活动区域。这一罕见的事件为我们提供了一个前所未有的机会来研究磁场对经过的太阳地震波的反应。在日震波扫过的两个黑子中都观测到磁场变化波，磁场和多普勒速度观测到的波的时距关系是相似的。测量的相位关系之间，以及振荡功率分布计算，多普勒速度变化和磁场变化与太阳地震波的比较，从背景波在相同地区的太阳黑子本影和半影分别。相位关系似乎支持这样的理论，即磁场变化波是由于与经过的太阳地震波相关的不透明度变化。相位和功率分布的比较表明，在太阳黑子中观察到的背景磁场变化是各种波模式的组合，快磁声波只占这些磁场变化的一小部分。
We report on the detection of waves of magnetic-field variations that were associated with flare-excited sunquake waves. An X-9.3 flare that occurred on 2017 September 6 excited strong sunquakes, and the sunquake waves were observed sweeping across the flare’s host active region. This rare event gives us an unprecedented opportunity to study responses of magnetic field to passing sunquake waves. A wave of magnetic-field variations was observed in each of the two sunspots that the sunquake waves swept through, and the time–distance relations for the waves observed in magnetic field and Doppler velocity are similar. The phase relations measured between, as well as the oscillatory power distributions calculated from, the Doppler velocity variations and magnetic-field variations associated with the sunquake waves are compared with those obtained from the background waves in the same areas of the sunspot umbra and penumbra separately. The phase relations seem to favor the theory that the waves of magnetic variations are owing to opacity changes associated with the passing sunquake waves. The comparisons of phases and power distributions indicate that the background magnetic variations observed in sunspots are a combination of various wave modes, and fast magnetoacoustic waves only account for a fraction of those magnetic variations.