爆發型與限制型閃焰前之活躍區足點電漿特徵研究;Plasma Characteristics of Active Region Footpoints Before Eruptive and Confined Flares

NCUIR > College of Earth Sciences > Graduate Institute of Space Science > Department of Earth Sciences > Item 987654321/94667

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/94667

Title:	爆發型與限制型閃焰前之活躍區足點電漿特徵研究;Plasma Characteristics of Active Region Footpoints Before Eruptive and Confined Flares
Authors:	江澄穎;Chiang, Cheng-Ying
Contributors:	太空科學與工程學系
Keywords:	太陽爆發活動;日冕特徵;太陽閃焰;日冕物質拋射;極紫外線觀測;Solar activity;Solar coronal;Solar Flare;Coronal Mass Ejection (CME);EUV radiation
Date:	2024-07-29
Issue Date:	2024-10-09 15:22:54 (UTC+8)
Publisher:	國立中央大學
Abstract:	太陽閃焰與日冕物質拋射是發生於太陽活躍區中、且普遍被認為是由於磁場重組造成的重要爆發現象，但並不一定伴隨出現，而本研究將爆發現象分為有伴隨日冕物質拋射的爆發型閃焰，與沒有伴隨日冕物質拋射的限制型閃焰，並比較兩種類型閃焰的差異。過往的研究大多著重在討論兩種閃焰事件的磁場特性，本研究則希望探討過往鮮少討論的電漿表現，且參考Imada et al. (2014)與Harra et al. (2009)的研究結果，針對閃焰發生前活躍區足點的特徵變化進行分析。本研究使用SDO/AIA的影像資料與Hinode/EIS的光譜資料，分別以差分發射計量分析與光譜分析，討論M1.8爆發型閃焰的活躍區AR12473，以及發生C9.9限制型閃焰的活躍區AR11158中共四個足點區域的都卜勒速度、非熱速率與密度等電漿相關性質，在兩種閃焰發生前各自有何變化。從分析結果可歸納出兩種閃焰事件確實有不同的閃焰前特徵：爆發型閃焰發生前，其活躍區足點的上升電漿流速度、非熱速率有增強之趨勢，且密度有所下降；而限制型閃焰發生前，活躍區足點的上升電漿流速沒有明顯增強，甚至有減弱之趨勢，且密度在限制型閃焰前有明顯的增加。為了說明本研究之結果，我們提出以閃焰前活躍區演化相關活動，如日冕環擴張等，提供可能的物理圖像解釋來說明目前的研究結果，希望能對太陽爆發事件能有更進一步的理解。;Solar flares and coronal mass ejections (CMEs) are significant eruptions occurring in solar active regions and are generally believed to be caused by magnetic reconfiguration. However, these activities do not always occur simultaneously, so eruptions are categorized into eruptive flares, which are accompanied by CMEs, and confined flares, which are not, in this paper. Most research has focused on the magnetic properties to discuss the differences between the two types of flares. In this study, following the results of Imada et al. (2014) and Harra et al. (2009), the plasma characteristic changes in footpoints of active regions before the flare occurrences are targeted to the main purpose, which has been less discussed. To investigate both types of flares, imaging data from SDO/AIA and spectral data from Hinode/EIS, applying differential emission measure (DEM) analysis and spectral analysis, respectively, are utilized to discuss the Doppler velocity, non-thermal speed, and density of plasma in four footpoint regions within the active regions AR12473, associated with an M1.8 eruptive flare, and AR11158, associated with a C9.9 confined flare. The results suggest distinct pre-flare characteristics for the two flare events: before eruptive flares, there is a trend of increasing upward plasma flow velocity and non-thermal speed in the footpoints of the active region, along with a decrease in density; whereas before confined flares, the upward plasma flow velocity does not significantly increase and may even decrease, with a noticeable increase in density. To explain these findings, a possible scenario related to pre-flare active region evolution, such as coronal loop expansion, is proposed in this paper, aiming at a more complete understanding of solar eruptions.
Appears in Collections:	[Graduate Institute of Space Science] Department of Earth Sciences

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	32	View/Open

社群 sharing

Loading...