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Temporal variation of hemispheric solar rotation

Research in Astronomy and Astrophysics 2012年第2期12卷 187-200页

作者： jing-lan xie 1,2.xiang-jun shi 1,{2.,2. national astronomical observatories /yunnan observatory,chinese academy of sciences,kunming 650011,China 2.Graduate University of chinese academy of sciences,Beijing 100049,China national astronomical {2./ yunnan observatory Chinese Academy of Sciences Kunming 650011 China Graduate University of chinese academy of sciences Beijing 100049 China

The daily sunspot numbers of the whole disk as well as the northern and southern hemispheres from 1945 January 1 to 2.10 December 31 are used to investi- gate the temporal variation of rotational cycle length through the continuous wavelet transformation analysis method. Auto-correlation function analysis of daily hemi- spheric sunspot numbers shows that the southern hemisphere rotates faster than the northern hemisphere. The results obtained from the wavelet transformation analysis are that no direct relationship exists between the variation trend of the rotational cy- cle length and the solar activity in the two hemispheres and that the rotational cycle length of both hemispheres has no significant period appearing at 11 yr, but has a sig- nificant period of about 7.6 yr. Analysis concerning the solar cycle dependence of the rotational cycle length shows that acceleration seems to appear before the minimum time of solar activity in the whole disk and the northern hemisphere, respectively. Furthermore, the cross-correlation study indicates that the rotational cycle length of the two hemispheres has different phases, and that the rotational cycle length of the whole disk as well as the northern and southern hemispheres, also has phase shifts with corresponding solar activity. In addition, the temporal variation of the north-south （N- S） asymmetry of the rotational cycle length is also studied. This displays the same variation trend as the N-S asymmetry of solar activity in a solar cycle, as well as in the considered time interval, and has two significant periods of 7.7 and 17.5 yr. Moreover, the rotational cycle length and the N-S asymmetry of solar activity are highly corre- lated. It is inferred that the northern hemisphere should rotate faster at the beginning of solar cycle 2..

关键词： Sun: activity - Sun: rotation - Sun: sunspot

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Observation of spectral lines in the exceptional GRB 2.1009A

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 187-206页

作者： Yan-Qiu Zhang Shao-Lin Xiong Ji-Rong Mao Shuang-Nan Zhang Wang-chen xue Chao Zheng Jia-Cong Liu Zhen Zhang Xi-Lu Wang Ming-Yu Ge Shu-xu Yi Li-Ming Song Zheng-Hua An Ce Cai Xin-Qiao Li Wen-Xi Peng Wen-jun Tan chen-Wei Wang {2.-Yang Wen Yue Wang Shuo Xiao Fan Zhang Peng Zhang shi-Jie Zheng Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of chinese academy of sciences Beijing 100049China yunnan observatories Chinese Academy of SciencesKunming 650011China Center for astronomical Mega-Science Chinese Academy of SciencesBeijing 100012China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China College of Physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal UniversityShijiazhuang 050024China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China College of Electronic and Information Engineering Tongji UniversityShanghai 201804China

As the brightest gamma-ray burst ever observed,GRB 2.1009A provided a precious opportunity to explore spectral line *** this article,we performed a comprehensive spectroscopy analysis of GRB 2.1009A jointly with GECAM-C and Fermi/GBM data to search for emission and absorption *** the first time we investigated the line feature throughout this GRB including the most bright part where many instruments suffered problems,and identified prominent emission lines in multiple time *** central energy of the Gaussian emission line evolves from about 37 to 6 MeV,with a nearly constant ratio(about 10%)between the line width and central ***,we find that both the central energy and the energy flux of the emission line evolve with time as a power law decay with power law index of–1 and–2.*** suggest that the observed emission lines most likely origin from the blue-shifted electron positron pair annihilation 511 ke V *** find that a standard high latitude emission scenario cannot fully interpret the observation,thus we propose that the emission line comes from some dense clumps with electron positron pairs traveling together with the *** this scenario,we can use the emission line to directly,for the first time,measure the bulk Lorentz factor of the jet(Γ)and reveal its time evolution(i.e.,Γ~t^(-1))during the prompt ***,we find that the flux of the annihilation line in the co-moving frame keeps *** discoveries of the spectral line features shed new and important lights on the physics of GRB and relativistic jet.

关键词： GRB GRB 2.1009A emission line

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日冕分米波射电甚短周期脉动的观测证据

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天文学报 2003年第2期44卷 139-146页

作者：谢瑞祥汪敏施硕彪许春李维华颜毅华中国科学院国家天文台云南天文台昆明650011 中国科学院国家天文台北京100012

利用国家天文台云南天文台“分米波(700—1500 MHz)射电频谱仪”和“四波段太阳射电高时间分辨率同步观测系统”分别于2.01年6月2.日和1990年7月30日观测到了两个稀少事件,前者是一个小射电爆发,其上升相伴随有短周期(约2.、40和100毫秒... 详细信息

利用国家天文台云南天文台“分米波(700—1500 MHz)射电频谱仪”和“四波段太阳射电高时间分辨率同步观测系统”分别于2.01年6月2.日和1990年7月30日观测到了两个稀少事件,前者是一个小射电爆发,其上升相伴随有短周期(约2.、40和100毫秒)的脉动,后者是一个射电大爆发,在2.40 MHz上产生了周期约30毫秒的射电脉动。还着重讨论其甚短周期(如2.—40毫秒)的脉动现象,甚短周期脉动可能是归因干起源在日冕深处不稳定区域的哨声波束周期链对射电辐射的凋制,或沉降电子束驱动的静电高混杂波,经由波-波非线性相互作用导致甚短周期的射电脉动。

关键词：日冕射电辐射磁场脉动

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Observational Characteristics of Radio Emission Related to Multi-polar Magnetic Configuration

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chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 508-518页

作者： Min Wang Rui-xiang xie Chun {2. Shuo-Biao shi Yi-Hua Yan national astronomical {2. Yunnan Observatory Chinese Academy of SciencesKunming 650011 national astronomical {2. Chinese Academy of Sciences Beijing 100012

We present a large complex radio burst and its associated fast time structures observed on 2.01 April 10 in the frequency range of 0.65-7.6 GHz. The NoRH radio image observation shows very complex radio source structures which include preexisting, newly emerging, submerging/cancelling polarities and a bipolar, a tripolar （a ＇bipolar ＋ remote unipolar＇）, and a quadrupolar structure. This suggests that the radio burst is generated from a very complicated loop structure. According to the spectral and image observations, we assume that the beginning of this flare was caused by a single bipolar loop configuration with a ‘Y-type＇ re- connection structure. A composite of radio continuum and fast time structures is contained in this flare. The various fast radio emission phenomena include normal and reverse drifting type Ⅲ bursts, and slowly drifting and no-drift structures. The tripolar configurations may form a double-loop with a ＇three-legged＇ struc- ture, which is an important source of the various types of fast time structures. The two-loop reconnection model can lead simultaneously to electron acceleration and corona heating. We have also analyzed the behaviors of coronal magnetic polarities and the emission processes of different types radio emission qualitatively. Interactions of a bipolar or multi-polar loop are consistent with our observational results. Our observations favor the magnetic reconnection configurations of the ‘inverted Y-type＇（bipolar） and the ‘three-legged＇ structures （tripolar or quadrupo- lar）.

关键词： Sun: radio radiation - Sun: activity - Sun: flares

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2.二次触发型太阳耀斑的射电时间轮廓及其日冕磁结构

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天文研究与技术 2006年第3期3卷 247-257页

作者：谢瑞祥郝龙飞颜毅华许春刘玉英施硕彪李维华中国科学院国家天文台云南天文台云南昆明650011 中国科学院国家天文台北京100012

利用国家天文台（北京和昆明）的射电频谱仪（频段为0．65～7．6GHz）和相关的NORH／17GHz射电以及TRACE／171^°A EUV和Yohkoh／SXT的观测资料，分析了2.01／04／10和10／19的2.共生精细时间结构的稀有事件，这2.事件的射电爆发时间... 详细信息

利用国家天文台（北京和昆明）的射电频谱仪（频段为0．65～7．6GHz）和相关的NORH／17GHz射电以及TRACE／171^°A EUV和Yohkoh／SXT的观测资料，分析了2.01／04／10和10／19的2.共生精细时间结构的稀有事件，这2.事件的射电爆发时间轮廓和观测特征相似，通过这2.事件的微波（17GHz）偏振观测资料的比较，发现这2.射电爆发均由包含多重（4极）磁结构的复杂活动区引起，特别指出这2.耀斑最后都导致了耀斑后相的分米波射电爆发（第二次触发耀斑），这可能是后环引起的射电爆发。它们都分别对应于双极磁位形，表明这两次触发耀斑是由相似的耀斑模型产生。2.分米波爆发可能是相似（homologous）耀斑的射电表现，可以推测这两次耀斑的驱动器可能皆是磁流浮现或对消（因为源区有新的单或双极出现或消失），而它们的触发器皆是由双极反向Y型位形（具有一个双极拱的单磁流系统）的磁重联，耀斑后环的演化是导致耀斑后相分米波射电爆发的必要条件。我们认为，这双带耀斑对应的宽带射电爆发辐射机制是回旋同步加速辐射过程，而耀斑后相的窄带分米波爆发的辐射机制是等离子体辐射过程．

关键词：太阳射电辐射日冕磁结构耀斑触发

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