中国科学院紫金山天文台机构知识库
Advanced  
PMO OpenIR  > 太阳活动的多波段观测研究团组  > 期刊论文
题名: CHROMOSPHERIC CONDENSATION AND QUASI-PERIODIC PULSATIONS IN A CIRCULAR-RIBBON FLARE
作者: Zhang, Q. M.; Li, D.; Ning, Z. J.
刊名: ASTROPHYSICAL JOURNAL
出版日期: 2016
卷号: 832, 期号:1, 页码:65
英文摘要: In this paper, we report our multiwavelength observations of the C3.1 circular-ribbon flare SOL2015-10-16T10: 20 in active region (AR) 12434. The flare consisted of a circular flare ribbon (CFR), an inner flare ribbon (IFR) inside it, and a pair of short parallel flare ribbons (PFRs). The PFRs located to the north of the IFR were most striking in the Interface Region Imaging Spectrograph (IRIS) 1400 and 2796 angstrom images. For the first time, we observed the circular-ribbon flare in the Ca II H line of the Solar Optical Telescope on board Hinode, which has a similar shape as observed in the Atmospheric Imaging Assembly 1600 angstrom on board the Solar Dynamic Observatory (SDO). Photospheric line-of-sight magnetograms from the Helioseismic and Magnetic Imager on board SDO show that the flare is associated with positive polarities with a negative polarity inside. The IFR and CFR were cospatial with the negative polarity and positive polarities, implying the existence of a magnetic null point (B = 0) and a dome-like spine-fan topology. During the impulsive phase of the flare, " two-step" raster observations of IRIS with a cadence of 6 s and an exposure time of 2 s showed plasma downflow at the CFR in the Si IV.1402.77 line (log T approximate to 4.8), suggesting chromospheric condensation. The downflow speeds first increased rapidly from a few km s(-1) to the peak values of 45-52 km s(-1), before decreasing gradually to the initial levels. The decay timescales of condensation were 3-4 minutes, indicating ongoing magnetic reconnection. Interestingly, the downflow speeds are positively correlated with the logarithm of the Si IV line intensity and time derivative of the GOES soft X-ray (SXR) flux in 1-8 angstrom. The radio dynamic spectra are characterized by a type III radio burst associated with the flare, which implies that the chromospheric condensation was most probably driven by nonthermal electrons. Using an analytical expression and the peak Doppler velocity, we derive the lower limit of energy flux of the precipitating electrons, i.e., 0.65 x 10(10) erg cm(-2) s(-1). The Si IV line intensity and SXR derivative show quasi-periodic pulsations with periods of 32-42 s, which are likely caused by intermittent null-point magnetic reconnections modulated by the fast wave propagating along the fan surface loops at a phase speed of 950-1250 km s(-1). Periodic accelerations and precipitations of the electrons result in periodic heating observed in the Si IV line and SXR.
WOS记录号: WOS:000400500700002
Citation statistics:
内容类型: 期刊论文
URI标识: http://libir.pmo.ac.cn/handle/332002/17057
Appears in Collections:太阳活动的多波段观测研究团组_期刊论文

Files in This Item:
File Name/ File Size Content Type Version Access License
2016209.pdf(7489KB)期刊论文作者接受稿限制开放View 联系获取全文
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[Zhang, Q. M.]'s Articles
[Li, D.]'s Articles
[Ning, Z. J.]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[Zhang, Q. M.]‘s Articles
[Li, D.]‘s Articles
[Ning, Z. J.]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
文件名: 2016209.pdf
格式: Adobe PDF
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2018  中国科学院紫金山天文台 - Feedback
Powered by CSpace