中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
首页 机构 成果 学者
  
  1. CAS IR Grid
  2. 国家天文台
  3. 中国科学院国家天文台
Plasma injection into a solar coronal loop

文献类型：期刊论文

作者Li, L. P.1,2,3; Peter, H.2
刊名ASTRONOMY & ASTROPHYSICS
出版日期2019-06-19
卷号626页码:14
关键词Sun: corona Sun: transition region Sun: UV radiation line: profiles techniques: spectroscopic
ISSN号1432-0746
DOI10.1051/0004-6361/201935165
英文摘要Context. The details of the spectral profiles of extreme UV emission lines from solar active regions contain key information for investigating the structure, dynamics, and energetics of the solar upper atmosphere. Aims. We characterize the line profiles not only through the Doppler shift and intensity of the bulk part of the profile. More importantly, we investigate the excess emission and asymmetries in the line wings to study twisting motions and helicity. Methods. We used a raster scan of the Interface Region Imaging Spectrograph (IRIS) in an active region. We concentrated on the Si Iv line at 1394 angstrom, which forms just below 0.1 MK, and followed the plasma that moves in a cool loop from one footpoint to the other. We applied single-Gaussian fits to the line core, determined the excess emission in the red and blue wings, and derived the asymmetry of the red and blue wings. Results. The blue wing excess at one footpoint shows injection of plasma into the loop that then flows to the other side. At the same footpoint, redshifts in the line core indicate that energy is deposited at around 0.1 MK. The enhanced pressure would then push the cool plasma down and inject some plasma into the loop. In the middle part of the loop, the spectral tilts of the line profiles indicate that the magnetic field has a helical structure, and the line wings are symmetrically enhanced. This is an indication that the loop is driven through the injection of helicity at the loop feet. Conclusions. If the loop is driven to be helical, then the magnetic field can be expected to be in a turbulent state, as has been shown by existing magnetohydrodynamics models. The turbulent motions might explain the (symmetric) line wing enhancements that have also been seen in loops at coronal temperatures, but are not understood so far.
WOS关键词TRANSITION-REGION ; NONTHERMAL VELOCITIES ; EXPLOSIVE EVENTS ; SUN ; TELESCOPE ; DYNAMICS ; OUTFLOWS ; UPFLOWS ; MOTIONS ; HINODE
资助项目ESA ; Norwegian Space Centre ; National Foundations of China[11673034] ; National Foundations of China[11533008] ; National Foundations of China[11790304] ; National Foundations of China[11773039] ; Chinese Academy of Sciences[QYZDJ-SSW-SLH050]
WOS研究方向Astronomy & Astrophysics
语种英语
WOS记录号WOS:000472022700005
出版者EDP SCIENCES S A
资助机构ESA ; ESA ; Norwegian Space Centre ; Norwegian Space Centre ; National Foundations of China ; National Foundations of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; ESA ; ESA ; Norwegian Space Centre ; Norwegian Space Centre ; National Foundations of China ; National Foundations of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; ESA ; ESA ; Norwegian Space Centre ; Norwegian Space Centre ; National Foundations of China ; National Foundations of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; ESA ; ESA ; Norwegian Space Centre ; Norwegian Space Centre ; National Foundations of China ; National Foundations of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences
源URL[http://ir.bao.ac.cn/handle/114a11/26583]  
专题中国科学院国家天文台
通讯作者Li, L. P.
作者单位1.Chinese Acad Sci, CAS Key Lab Solar Act, Natl Astron Observ, Beijing 100101, Peoples R China
2.Max Planck Inst Solar Syst Res MPS, D-37077 Gottingen, Germany
3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式
GB/T 7714		 Li, L. P.,Peter, H.. Plasma injection into a solar coronal loop[J]. ASTRONOMY & ASTROPHYSICS,2019,626:14.
APA Li, L. P.,&Peter, H..(2019).Plasma injection into a solar coronal loop.ASTRONOMY & ASTROPHYSICS,626,14.
MLA Li, L. P.,et al."Plasma injection into a solar coronal loop".ASTRONOMY & ASTROPHYSICS 626(2019):14.

入库方式： OAI收割

来源：国家天文台

浏览0
下载0
收藏0
其他版本

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。