A magnetic reconnection model for the hot explosion with both ultraviolet and Hα wing emissions

doi:10.1051/0004-6361/202347012

YNAO OpenIR > 太阳物理研究组

	A magnetic reconnection model for the hot explosion with both ultraviolet and Hα wing emissions
	Cheng GC(程冠冲)1,2,3 ; Ni L(倪蕾)1,3,4,5 ; Chen, Yajie 2; Lin J(林隽)1,3,4,5
发表期刊	Astronomy and Astrophysics
	2024-04-30
卷号	685
DOI	10.1051/0004-6361/202347012
产权排序	第1完成单位
收录类别	SCI ; EI
关键词	magnetic reconnection magnetohydrodynamics (MHD) plasmas Sun: activity Sun: chromosphere Sun: UV radiation
摘要	Context. Ellerman bombs (EBs) with significant Hα wing emissions and ultraviolet bursts (UV bursts) with strong Si IV emissions are two kinds of small transient brightening events that occur in the low solar atmosphere. The statistical observational results indicate that about 20% of the UV bursts connect with EBs. While some promising models exist for the formation mechanism of colder EBs in conjunction with UV bursts, the topic remains an area of ongoing research and investigation. Aim. We numerically investigated the magnetic reconnection process between the emerging arch magnetic field and the lower atmospheric background magnetic field. We aim to find out if the hot UV emissions and much colder Hα wing emissions can both appear in the same reconnection process and how they are located in the reconnection region. Methods. The open-source code NIRVANA was applied to perform the 2.5D magnetohydrodynamic (MHD) simulation. We developed the related sub-codes to include the more realistic radiative cooling process for the photosphere and chromosphere and the time-dependent ionization degree of hydrogen. The initial background magnetic field is 600 G, and the emerged magnetic field in the solar atmosphere is of the same magnitude, meaning that it results in a low- β magnetic reconnection environment. We also used the radiative transfer code RH1.5D to synthesize the Si IV and Hα spectral line profiles based on the MHD simulation results. Results. Magnetic reconnection between emerged and background magnetic fields creates a thin, curved current sheet, which then leads to the formation of plasmoid instability and the nonuniform density distributions. Initially, the temperature is below 8000 K. As the current sheet becomes more vertical, denser plasmas are drained by gravity, and hotter plasmas above 20 000 K appear in regions with lower plasma density. The mix of hot tenuous and much cooler dense plasmas in the turbulent reconnection region can appear at about the same height, or even in the same plasmoid. Through the reconnection region, the synthesized Si IV emission intensity can reach above 106 erg s−1 sr−1 cm−2 Å−1 and the spectral line profile can be wider than 100 km s−1, the synthesized Hα line profile also show the similar characteristics of a typical EB. The turbulent current sheet is always in a dense plasma environment with an optical depth larger than 6.5 × 10−5 due to the emerged magnetic field pushing high-density plasmas upward. Conclusions. Our simulation results indicate that the cold EB and hot UV burst can both appear in the same reconnection process in the low chromosphere, the EB can either appear several minutes earlier than the UV burst, or they can simultaneously appear at the similar altitude in a turbulent reconnection region below the middle chromosphere. © The Authors 2024.
资助项目	National Key R&D Program of China[2022YFF0503003]; National Key R&D Program of China[2022YFF0503000]; National Key R&D Program of China[2022YFF0503804]; National Key R&D Program of China[2022YFF0503800]; NSFC[11973083]; NSFC[11933009]; Strategic Priority Research Program of CAS[XDA17040507]; Youth Innovation Promotion Association CAS[Y2021024]; Applied Basic Research of Yunnan Province in China[2018FB009]; Yunling Talent Project for the Youth; Group for Innovation of Yunnan Province[2018HC023]; Yunling Scholar Project of the Yunnan Province; Yunnan Key Laboratory of Solar Physics and Space Science[202205AG070009]
项目资助者	National Key R&D Program of China[2022YFF0503003, 2022YFF0503000, 2022YFF0503804, 2022YFF0503800] ; NSFC[11973083, 11933009] ; Strategic Priority Research Program of CAS[XDA17040507] ; Youth Innovation Promotion Association CAS[Y2021024] ; Applied Basic Research of Yunnan Province in China[2018FB009] ; Yunling Talent Project for the Youth ; Group for Innovation of Yunnan Province[2018HC023] ; Yunling Scholar Project of the Yunnan Province ; Yunnan Key Laboratory of Solar Physics and Space Science[202205AG070009]
语种	英语
学科领域	天文学 ; 太阳与太阳系
文章类型	Article
出版者	EDP SCIENCES S A
出版地	17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE
ISSN	0004-6361
URL	查看原文
WOS记录号	WOS:001231008100006
WOS研究方向	Astronomy & Astrophysics
WOS类目	Astronomy & Astrophysics
关键词[WOS]	PLASMOID-MEDIATED RECONNECTION ; MULTILEVEL RADIATIVE-TRANSFER ; ELLERMAN BOMBS ; SOLAR CHROMOSPHERE ; FLUX EMERGENCE ; H-ALPHA ; BURSTS ; IRIS ; ATMOSPHERE ; HYDROGEN
EI入藏号	20241916067506
EI主题词	Magnetohydrodynamics
EI分类号	615.3 Magnetohydrodynamics (MHD) Power Generation - 701 Electricity and Magnetism - 701.2 Magnetism: Basic Concepts and Phenomena - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 932.3 Plasma Physics
引用统计	被引频次：1[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ynao.ac.cn/handle/114a53/27205
专题	太阳物理研究组
作者单位	1.Yunnan Observatories, Chinese Academy of Sciences, Yunnan, Kunming, 650216, China; 2.Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, Göttingen, 37077, Germany; 3.University of Chinese Academy of Sciences, Beijing, 100049, China; 4.Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, China; 5.Yunnan Key Laboratory of Solar Physics and Space Science, Kunming, 650216, China
第一作者单位	中国科学院云南天文台
推荐引用方式 GB/T 7714	Cheng GC,Ni L,Chen, Yajie,et al. A magnetic reconnection model for the hot explosion with both ultraviolet and Hα wing emissions[J]. Astronomy and Astrophysics,2024,685.
APA	程冠冲,倪蕾,Chen, Yajie,&林隽.(2024).A magnetic reconnection model for the hot explosion with both ultraviolet and Hα wing emissions.Astronomy and Astrophysics,685.
MLA	程冠冲,et al."A magnetic reconnection model for the hot explosion with both ultraviolet and Hα wing emissions".Astronomy and Astrophysics 685(2024).

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