Do All Interplanetary Coronal Mass Ejections Have a Magnetic Flux Rope Structure Near 1 au?
文献类型:期刊论文
作者 | Song,H. Q.5; Zhang,J.1; Cheng,X.3; Li,G.2; Hu,Q.2; Li,L. P.4; Chen,S. J.5; Zheng,R. S.5; Chen,Y.5 |
刊名 | The Astrophysical Journal Letters |
出版日期 | 2020-09-24 |
卷号 | 901期号:2 |
ISSN号 | 2041-8205 |
关键词 | Solar coronal mass ejections Solar coronal mass ejection shocks Solar storm |
DOI | 10.3847/2041-8213/abb6ec |
英文摘要 | Abstract Interplanetary coronal mass ejections (ICMEs) often consist of a shock wave, sheath region, and ejecta region. The ejecta regions are divided into two broad classes: magnetic clouds (MCs) that exhibit the characteristics of magnetic flux ropes, and non-magnetic clouds (NMCs) that do not. As CMEs result from eruption of magnetic flux ropes, it is important to answer why NMCs do not have the flux rope features. One claims that NMCs lose their original flux rope features due to the interactions between ICMEs or ICMEs and other large-scale structures during their transit in the heliosphere. The other attributes this phenomenon to the geometric selection effect; i.e., when an ICME has its nose (flank, including leg and non-leg flanks) pass through the observing spacecraft, the MC (NMC) features will be detected along the spacecraft trajectory within the ejecta. In this Letter, we examine which explanation is more reasonable through the geometric properties of ICMEs. If the selection effect leads to different ejecta types, MCs should have narrower sheath region compared to NMCs from the statistical point of view, which is confirmed by our statistics. In addition, we find that NMCs have similar sizes in solar cycles 23 and 24, and NMCs are smaller than MCs in cycle 23 but larger than MCs in cycle 24. This suggests that most NMCs have their leg flank pass through the spacecraft. Our geometric analyses support that all ICMEs should have a magnetic flux rope structure near 1 au. |
语种 | 英语 |
出版者 | The American Astronomical Society |
WOS记录号 | IOP:2041-8205-901-2-ABB6EC |
源URL | [http://ir.bao.ac.cn/handle/114a11/62855] |
专题 | 中国科学院国家天文台 |
通讯作者 | Song,H. Q. |
作者单位 | 1.Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA 2.Department of Space Science and CSPAR, The University of Alabama in Huntsville, Huntsville, AL 35805, USA 3.School of Astronomy and Space Science, Nanjing University, Nanjing, Jiangsu 210093, People’s Republic of China 4.CAS Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100101, People’s Republic of China 5.Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, and Institute of Space Sciences, Shandong University, Weihai, Shandong 264209, People’s Republic of China; hqsong@sdu.edu.cn |
推荐引用方式 GB/T 7714 | Song,H. Q.,Zhang,J.,Cheng,X.,et al. Do All Interplanetary Coronal Mass Ejections Have a Magnetic Flux Rope Structure Near 1 au?[J]. The Astrophysical Journal Letters,2020,901(2). |
APA | Song,H. Q..,Zhang,J..,Cheng,X..,Li,G..,Hu,Q..,...&Chen,Y..(2020).Do All Interplanetary Coronal Mass Ejections Have a Magnetic Flux Rope Structure Near 1 au?.The Astrophysical Journal Letters,901(2). |
MLA | Song,H. Q.,et al."Do All Interplanetary Coronal Mass Ejections Have a Magnetic Flux Rope Structure Near 1 au?".The Astrophysical Journal Letters 901.2(2020). |
入库方式: OAI收割
来源:国家天文台
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