Coronal changes associated with a disappearing filament
Coronal changes associated with a disappearing filament
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与消失的细丝相关的冠状变化
DOI：
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发表时间：
1975
期刊：
影响因子：
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通讯作者：
J. P. M. Guire
中科院分区：
文献类型：
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作者：
N. R. SheeleyJr.;J. D. Bohlin;G. Brueckner;J. Purcell;V. Scherrer;R. Tousey;J. B. SmithJr.;D. Speich;Einar Tandberg;R. Wilson;A. Loach;Richard B. Hoover;J. P. M. Guire
本文描述了1974年1月18日Skylab/ATM对太阳圆板中心附近暗条消失事件的观测。当暗条消失时，附近的日冕等离子体被加热到超过6 × 106 K的温度。在软X射线通量增加的11/3小时期间，日冕发射模式发生了变化。这种变化似乎包括环状日冕结构的形成和明显的扩张，直到几天后它绕过西翼才消失。X射线和微波射电流量的时间历史显示出著名的渐变上升和下降（GRF）签名，这表明1月18日的事件可能具有广泛的X射线和射电事件的特性。为了追求这个想法，我们检查了其他空间分辨的Skylab/ATM观测的长持续时间X射线事件，看看它们可能有什么共同的特征。在为期9个月的天空实验室使命中，发生了19次类似的长寿命SOLRAD X射线事件，这些事件要么属于GRF，要么属于“后爆发”射电分类。其中16个事件发生在HAO/ATM日冕观测期间，这16个事件中有7个事件发生在NRL/ATM无狭缝摄谱仪和MSFC-A/ATM X射线望远镜观测期间。这些事件的列表表明，所有长寿命的SOLRAD X射线爆发都涉及外日冕的瞬变，至少三分之二的爆发涉及爆发或日珥的主要激活。此外，这些观测结果表明，长寿命SOLARD事件的特征是在X射线发射的下降阶段，较低日冕中出现新的发射环。然而，有时这些环在X射线事件后消失（如与“偶发日冕凝聚”相关的耀斑后环），有时这些环无限期地保留（如来自“永久日冕凝聚”的发射）。
This paper describes Skylab/ATM observations of the events associated with a disappearing filament near the center of the solar disk on January 18, 1974. As the filament disappeared, the nearby coronal plasma was heated to a temperature in excess of 6 × 106K. A change in the pattern of coronal emission occurred during the 11/3 hr period that the soft X-ray flux was increasing. This change seemed to consist of the formation and apparent expansion of a loop-like coronal structure which remained visible until its passage around the west limb several days later. The time history of the X-ray and microwave radio flux displayed the well-known gradual-rise-and-fall (GRF) signature, suggesting that this January 18 event may have properties characteristic of a wide class of X-ray and radio events.In pursuit of this idea, we examined other spatially-resolved Skylab/ATM observations of long-duration X-ray events to see what characteristics they may have in common. Nineteen similar long-lived SOLRAD X-ray events having either the GRF or ‘post-burst’ radio classification occurred during the nine-month Skylab mission. Sixteen of these occurred during HAO/ATM coronagraph observations, and 7 of these 16 events occurred during observations with both the NRL/ATM slitless spectrograph and the MSFC-A/ATM X-ray telescope. The tabulation of these events suggests that all long-lived SOLRAD X-ray bursts involve transients in the outer corona and that at least two-thirds of the bursts involve either the eruption or major activation of a prominence. Also, these observations indicate that long-lived SOLARD events are characterized by the appearance of new loops of emission in the lower corona during the declining phase of the X-ray emission. However, sometimes these loops disappear after the X-ray event (like the post-flare loops associated with a ‘sporadic coronal condensation’), and sometimes the loops remain indefinitely (like the emission from a ‘permanent coronal condensation’).