Hα Proxies for EIT Crinkles: Further Evidence for Preflare “Breakout”-Type Activity in an Ejective Solar Eruption
Hα Proxies for EIT Crinkles: Further Evidence for Preflare “Breakout”-Type Activity in an Ejective Solar Eruption
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EIT 皱纹的 Hα 代理：射流太阳喷发中前耀斑“突破”型活动的进一步证据
DOI：
10.1086/323374
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Haimin Wang
中科院分区：
文献类型：
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作者：
A. Sterling;R. Moore;J. Qiu;Haimin Wang
本文介绍了1998年5月1日22：30 UT附近NOAA活动区8210的一次爆发性耀斑的大熊座太阳天文台Hα观测结果。以前，使用SOHO航天器上的EUV成像望远镜（EIT），我们发现一种短暂的局部增亮模式，我们称之为“EIT褶皱”，出现在耀斑爆发时附近。这些EIT褶皱发生在活动区的一个位置，与剪切核心磁场分离，这是最强烈的喷发特征集中的地方。我们之前也发现，来自Yohkoh上软X射线望远镜（SXT）的高节奏图像表明，核心中的软X射线强度增强开始于EIT褶皱开始之后。利用Hα数据，我们发现了与EIT褶皱对应的远程耀斑增亮。光变曲线作为时间的函数的活动区的各个领域表明，几个远程耀斑增亮经历的强度增加之前，在核心区域的主要增亮的发病，与我们早期的研究结果一致，从EIT和SXT数据。这些时间关系与安提奥科斯及其同事提出的爆发模型一致，该模型提出爆发开始与核心区域上方的磁零点重联。我们的观察结果也与其他不涉及核心区域早期重新连接的拟议机制一致。作为一个推论，我们的观测结果与所谓的系绳切割模型不一致，该模型认为喷发始于核心的重新连接。Hα数据进一步表明，在EIT褶皱开始的时候，核心区域的暗条被激活，但是几乎没有任何暗条真正爆发，尽管存在与此事件相关的晕日冕物质抛射（CME）。
We present Hα observations from Big Bear Solar Observatory of an eruptive flare in NOAA Active Region 8210, occurring near 22:30 UT on 1998 May 1. Previously, using the EUV Imaging Telescope (EIT) on the SOHO spacecraft, we found that a pattern of transient, localized brightenings, which we call "EIT crinkles," appears in the neighborhood of the eruption near the time of flare onset. These EIT crinkles occur at a location in the active region well separated from the sheared core magnetic fields, which is where the most intense features of the eruption are concentrated. We also previously found that high-cadence images from the Soft X-ray Telescope (SXT) on Yohkoh indicate that soft X-ray intensity enhancements in the core begin after the start of the EIT crinkles. With the Hα data, we find remote flare brightening counterparts to the EIT crinkles. Light curves as functions of time of various areas of the active region show that several of the remote flare brightenings undergo intensity increases prior to the onset of principal brightenings in the core region, consistent with our earlier findings from EIT and SXT data. These timing relationships are consistent with the eruption onset mechanism known as the breakout model, introduced by Antiochos and colleagues, which proposes that eruptions begin with reconnection at a magnetic null high above the core region. Our observations are also consistent with other proposed mechanisms that do not involve early reconnection in the core region. As a corollary, our observations are not consistent with the so-called tether-cutting models, which say that the eruption begins with reconnection in the core. The Hα data further show that a filament in the core region becomes activated near the time of EIT crinkle onset, but little if any of the filament actually erupts, despite the presence of a halo coronal mass ejection (CME) associated with this event.