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Rotation Periods of Nine ROSAT Selected Solar-Type Stars

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chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 551-557页

作者： li-Feng Xing Shuang-Yi zhao Wei Su Yan Shen Xiao-Bin Zhang Jian-Yan Wei Department of Technology and Physics Zhengzhou Unversity of Light Industry Zhengzhou 450002 national astronomical observatories Chinese Academy of Sciences Beijing 100012 Department of Physics Xingtai University Xingtai 054001

We monitored 16 X-ray selected young solar-type stars for light variation and found appreciable periodic light variability with amplitudes of a few hundredths of a magni- tude in nine of the objects. Using the method of Phase Dispersion Minimization （PDM） and Fourier analysis （software PERIOD04）, the rotation periods of these stars were determined from the photometric data. The rotation periods of all nine stars are shorter than about 3 days. It is suggested that, as with the Pleiades cluster, small amplitude light variations are quite common among young solar-type stars with rotation periods around 3 days or less. This gives further evidence for the spin up of solar-type stars predicted by models of angular momentum evolution of pre-main sequence stars.

关键词： stars: late-type - stars: pre-main sequence - stars: rotation

Polar plumes observed at the total solar eclipse in 2009

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Science China(Physics,Mechanics & Astronomy) 2011年第10期54卷 1906-1910页

作者： YANG ShuHong ZHANG Jun ZHANG Zhiyong zhao zhaoWang liU YangBing SONG Qian YANG ShangBin BAO XingMing li LePing CHU Zhe li Ting Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Graduate University of chinese academy of sciences Beijing 100049 China

During the total solar eclipse of July 22, 2009, we carried out a white-light observation in Anji, Zhejiang, China. The aim wasto observe the polar plumes (PPs) with high spatial and temporal resolutions in white-light. With the observational data, weinvestigate the properties and evolution of the PPs and compare them with those of the low-latitude plumes (LPs). We find thatboth the PPs and the LPs have comparable lengths and widths, and the mean length and width are 300 Mm and 16 Mm, re-spectively. The average inclination angle (13 degree) of the PPs is smaller than that (32 degree) of the LPs. Generally, theplumes which are closer to the coronal hole center are more vertical. We trace the PPs and the LPs in the sequence of imagesand find that none of them disappears and no new one is created. Additionally, neither plasma outflow nor transverse oscilla-tion is observed. These imply that the evolution process of plumes is much longer than the timescale of eclipse.

关键词： Sun: eclipses Sun: corona Sun: evolution

A digital pulsar backend based on FPGA

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Research in Astronomy and Astrophysics 2017年第1期17卷 97-102页

作者： Jin-Tao luo Lan Chen Jin-lin Han Ali Esamdin Ya-Jun Wu Zhi-Xuan li Long-Fei Hao Xiu-Zhong Zhang national Time Service CenterChinese Academy of SciencesXi'an 710600China Key Laboratory of Time and Frequency Primary Standards Chinese Academy of SciencesXi'an 710600China national astronomical observatories Chinese Academy of SciencesBeijing 100012China Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Shanghai Institute of Technology Shanghai 200235China Yunnan observatories Chinese Academy of SciencesKunming 650011China Shanghai astronomical Observatory Chinese Academy of SciencesShanghai 200030China

A digital pulsar backend based on a Field Programmable Gate Array （FPGA） is developed. It is designed for incoherent de-dispersion of pulsar observations and has a maximum bandwidth of 512MHz. The channel bandwidth is fixed to 1 MHz, and the highest time resolution is 10 p.s. Testing observations were carried out using the Urumqi 25-m telescope administered by Xinjiang astronomical Observatory and the Kunming 40-m telescope administered by Yunnan observatories, targeting PSR J0332＋5434 in the L band and PSR J0437-4715 in the S band, respectively. The successful observation of PSR J0437-4715 demonstrates its ability to observe millisecond pulsars.

关键词： instrumentation miscellaneous - methods data analysis - pulsars general

Physical properties and catalog of EW-type eclipsing binaries observed byLAMOST

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Research in Astronomy and Astrophysics 2017年第8期17卷 109-122页

作者： Sheng-Bang Qian Jia-Jia He Jia Zhang li-Ying Zhu Xiang-Dong Shi Er-Gang zhao Xiao Zhou Yunnan observatories Chinese Academy of Sciences Kunming 650011 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Center for astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 China University of the chinese academy of sciences Beijing 100049 China

EW-type eclipsing binaries(hereafter called EWs)are strong interacting systems in which both component stars usually fill their critical Roche lobes and share a common *** EWs were discovered by several deep photometric surveys and there were about 40 785 EW-type binary systems listed in the international variable star index(VSX)by 2017 March 13.7938 of them were observed with LAMOST by 2016 November 30 and their spectral types were *** atmospheric parameters of 5363 EW-type binary stars were determined based on good spectroscopic *** the paper,those EWs are cataloged and their properties are *** distributions of orbital period(P),effective temperature(T),gravitational acceleration(log(g)),metallicity([Fe/H])and radial velocity(RV)are presented for these observed EW-type *** is shown that about 80.6% of sample stars have metallicity below zero,indicating that EW-type systems are old stellar *** is in agreement with the conclusion that EW binaries are formed from moderately close binaries through angular momentum loss via magnetic braking that takes a few hundred million to a few billion *** unusually high metallicities of a few percent of EWs may be caused by contamination of material from the evolution of unseen neutron stars or black holes in the *** correlations between orbital period and effective temperature,gravitational acceleration and metallicity are presented and their scatters are mainly caused by(i)the presence of third bodies and(ii)sometimes wrongly determined *** is shown that some EWs contain evolved component stars and the physical properties of EWs mainly depend on their orbital *** is found that extremely short-period EWs may be older than their long-period cousins because they have lower *** reveals that they have a longer timescale of pre-contact evolution and their formation and evolution are mainly driven by angular momentum loss vi

关键词： stars binaries close—stars binaries spectroscopic—stars binaries eclipsing—stars evolution

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

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Science China(Physics,Mechanics & Astronomy) 2020年第4期63卷 2-19页

作者： Shuang-Nan Zhang TiPei li FangJun Lu liMing Song YuPeng X u CongZhan liu yong Chen XueLei Cao QingCui Bu Zhi Chang Gang Chen li Chen TianXiang Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng yongWei Dong Yuan Yuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan Can Gungor ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin yongJie Jin Bing li ChengKui li Gang li MaoShun li Wei li Xian li XiaoBo li XuFang li YanGuo li ZiJian li ZhengWei li XiaoHua liang JinYuan liao GuoQing liu HongWei liu ShaoZhen liu XiaoJing liu Yuan liu YiNong liu Bo Lu XueFeng Lu Tao luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge Ou JinLu Qu Na Sai RenCheng Shang GuoHong Shen liang Sun Ying Tan lian Tao Youli Tuo Chen Wang ChunQin Wang GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BaiYang Wu BoBing Wu Mei Wu GuangCheng Xiao Shaolin Xiong linli Yan JiaWei Yang Sheng Yang YanJi Yang QiBin Yi Bin Yuan AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang ShenYi Zhangs Shu Zhang Tong Zhang WanChang Zhang Wei Zhang Wenzhao Zhang Yi Zhang YiFei Zhang yongJie Zhang Yue Zhang zhao Zhang Zhi Zhang Ziliang Zhang HaiSheng zhao XiaoFan zhao ShiJie Zheng JianFeng Zhou YuXuan Zhu Yue Zhu Renlin Zhuang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of chinese academy of sciences Beijing 100049China Department of Astronomy Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China Department of Astronomy Beijing Normal UniversityBeijing 100088China Department of Engineering Physics Tsinghua UniversityBeijing 100084China national astronomical observatories Chinese Academy of SciencesBeijing 100101China national Space Science Center Chinese Academy of SciencesBeijing 100190China

As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 Me V. It was designed to perform pointing, scanning and gamma-ray burst(GRB)observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be *** we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.

关键词： X-and γ-ray telescopes and instrumentation neutron stars black holes X-ray binaries γ-ray bursts

Emission lines of Boron, Carbon, Oxygen and Iron in Tokamak Plasma

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chinese Physics Letters 2011年第7期28卷 206-209页

作者： DI Long SHI Jian-Rong WANG Shou-Jun DONG Quan-li zhao Jing li Yu-Tong FU Jia WANG Fu-Di SHI Yue-Jiang WAN Bao-Nian zhao Gang ZHANG Jie Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012 Laboratory of Optical Physics Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190 Institute of Plasma Physics Chinese Academy of SciencesHefei 230031 Department of Physics Shanghai Jiao Tong UniversityShanghai 200240

The emission lines of B,C,O and Fe in tokamak plasma are *** spectra are compared with those calculated by the CHIANTI code,which is based on the collisional-radiative models with a large amount of accurate atomic *** agreement is obtained between the results of experiment and *** of the lines in the spectra are identified,and the relative number density ratios of B,C,O and Fe are *** is found that the processes of line formation in our experiment are similar to those in the stellar *** line-averaged electron density of the tokamak plasma is measured by the HCN laser,indicating a good agreement with the theoretical prediction by the density-dependent line ratio of Fe XXI.

关键词： computation tokamak Oxygen

Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring

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Research in Astronomy and Astrophysics 2021年第3期21卷 193-204页

作者： He-Xin liu Yue Huang Guang-Cheng Xiao Qing-Cui Bu Jin-Lu Qu Shu Zhang Shuang-Nan Zhang Shu-Mei Jia Fang-Jun Lu Xiang Ma lian Tao Wei Zhang li Chen li-Ming Song Ti-Pei li Yu-Peng Xu Xue-Lei Cao yong Chen Cong-Zhan liu Ce Cai Zhi Chang Gang Chen Tian-Xiang Chen Yi-Bao Chen Yu-Peng Chen Wei Cui Wei-Wei Cui Jing-Kang Deng yong-Wei Dong Yuan-Yuan Du Min-Xue Fu Guan-Hua Gao He Gao Min Gao Ming-Yu Ge Yu-Dong Gu Ju Guan Cheng-Cheng Guo Da-Wei Han Jia Huo Lu-Hua Jiang Wei-Chun Jiang Jing Jin yong-Jie Jin ling-Da Kong Bing li Cheng-Kui li Gang li Mao-Shun li Wei li Xian li Xiao-Bo li Xu-Fang li Yang-Guo li Zheng-Wei li Xiao-Hua liang Jing-Yuan liao Bai-Sheng liu Guo-Qing liu Hong-Wei liu Xiao-Jing liu Yi-Nong liu Bo Lu Xue-Feng Lu Qi luo Tao luo Bin Meng Yi Nang Jian-Yin Nie Ge Ou Na Sai Ren-Cheng Shang Xin-Ying Song liang Sun Ying Tan You-li Tuo Chen Wang Guo-Feng Wang Juan Wang ling-Jun Wang Weng-Shuai Wang Yu-Sa Wang Xiang-Yang Wen Bai-Yang Wu Bo-Bing Wu Mei Wu Shuo Xiao Shao-lin Xiong He Xu Jia-Wei Yang Sheng Yang Yan-Ji Yang Yi-Jung Yang Qi-Bin Yi Qian-Qing Yin Yuan You Ai-Mei Zhang Cheng-Mo Zhang Fan Zhang Hong-Mei Zhang Juan Zhang Tong Zhang Wan-Chang Zhang Wen-zhao Zhang Yi Zhang Yi-Fei Zhang yong-Jie Zhang Yuan-Hang Zhang Yue Zhang zhao Zhang Zhi Zhang Zi-liang Zhang Hai-Sheng zhao Xiao-Fan zhao Shi-Jie Zheng Yao-Guang Zheng Deng-Ke Zhou Jian-Feng Zhou Yu-Xuan Zhu Ren-lin Zhuang Yue Zhu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of chinese academy of sciences Chinese Academy of SciencesBeijing 100049China Institut fur Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls Universität72076 TubingenGermany Department of Astronomy Beijing Normal UniversityBeijing 100088China Department of Astronomy Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China College of Physics sciences&Technology Hebei UniversityBaoding 071002Hebei ProvinceChina

We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and *** outburst can be classified roughly into four different ***-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this ***,we study various physical quantities related to QPO *** QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain *** relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.

关键词： X-ray binaries black hole candidate QPO EXO 1846–031

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双活动星系核寄主星系的光谱合成分析

光谱学与光谱分析 2020年第1期40卷 290-293页

作者：汪梦欣罗阿理中国科学院光学天文重点实验室(国家天文台) 北京100101 中国科学院大学北京100049

星系并合会产生不同尺度距离的星系对甚至双活动星系核,同时在过程中会触发星暴以及超大质量黑洞的活动。在光谱上,当两个星系并合到kpc尺度时,其两个核的相互绕转在总光谱上会表现出窄线双峰谱线轮廓。以这个观测特性为起点,从郭守敬... 详细信息

星系并合会产生不同尺度距离的星系对甚至双活动星系核,同时在过程中会触发星暴以及超大质量黑洞的活动。在光谱上,当两个星系并合到kpc尺度时,其两个核的相互绕转在总光谱上会表现出窄线双峰谱线轮廓。以这个观测特性为起点,从郭守敬望远镜巡天的第四次释放数据(LAMOST DR4)中系统的搜寻带有窄发射线双峰特征的双AGN候选体。AGN的发射线光谱轮廓由发射线的若干种不同的动力学成分构成,主要可以分为三类,窄线成分(Hβ,[OⅢ], Hαand [NⅡ]),[OⅢ]的线翼、以及宽的Balmer发射线。基于LAMOST DR4河外光谱数据,应用了一套搜寻流程,在初始筛选(涉及到发射线的信噪比、等值宽度和红移)及目视检查挑选之后,通过建立的多高斯拟合模型挑选出在发射线的流量、半高全宽、窄线双峰之间速度分离程度等一系列参数上符合我们限制要求的样本,并借助于Baldwin-Phillips-Terlevich (BPT)图来鉴别每个成分的来源,确定出了28个双AGN候选体。为了获取更准确的星族成分并发现这类双AGN候选体样本的共有特性,对28个双AGN候选体的光谱流量用一个低阶多项式重新进行了修正并采用传统的统一插值和中值方法对其进行合并得到一条高信噪比光谱,并以目前已有的来源于LAMOST星系光谱数据的Ⅱ型AGN(单AGN)的复合光谱作为对照样本,采用STARliGHT软件分别拟合了合并的双AGN和对照的单AGN的光学光谱中的吸收线和连续谱。通过研究它们的星族特性及两者间的异同,发现与单AGN复合谱相比,双AGN候选体样本的合并谱具有更多中等年龄及老年星族的贡献,反映出更剧烈的中心黑洞。在金属丰度方面,单AGN的主导星族为太阳金属丰度的星族Z_⊙,而双AGN候选体合并谱中贡献较多的星族为亚太阳金属丰度星族0.2 Z_⊙和富金属丰度星族2.5 Z_⊙,表现出了差异性特征,也预示着这类样本中恒星形成历史更加复杂,呈现出了多样化。在幂律谱成分贡献方面在单、双AGN中老年星族都贡献了其大部分质量,但单AGN复合谱中幂律成分占比为8.2%,明显高于双AGN候选体合并谱中幂律成分的贡献。

关键词： LAMOST 双活动星系核光谱合成星族分析

An in-depth Exploration of LAMOST Unknown Spectra Based on Density Clustering

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Research in Astronomy and Astrophysics 2023年第5期23卷 52-65页

作者： Hai-Feng Yang Xiao-Na Yin Jiang-Hui Cai Yu-Qing Yang A-li luo Zhong-Rui Bai li-Chan Zhou Xu-Jun zhao Ya-ling Xun Shanxi Key Laboratory of Big Data Analysis and Parallel Computing Taiyuan University of Science and TechnologyTaiyuan 030024China School of Computer Science and Technology Taiyuan University of Science and TechnologyTaiyuan 030024China School of Computer Science and Technology North University of ChinaTaiyuan 030051China national astronomical observatories Chinese Academy of SciencesBeijing 100101China

Large sky Area Multi-Object fiber Spectroscopic Telescope(LAMOST) has completed the observation of nearly 20 million celestial objects,including a class of spectra labeled “Unknown.” Besides low signal-to-noise ratio,these spectra often show some anomalous features that do not work well with current *** this paper,a total of 637,889 “Unknown” spectra from LAMOST DR5 are selected,and an unsupervised-based analytical framework of “Unknown” spectra named SA-Frame(Spectra Analysis-Frame) is provided to explore their origins from different *** SA-Frame is composed of three parts:NAPC-Spec clustering,characterization and origin ***,NAPC-Spec(Nonparametric density clustering algorithm for spectra) characterizes different features in the “unknown” spectrum by adjusting the influence space and divergence distance to minimize the effects of noise and high dimensionality,resulting in 13 ***,characteristic extraction and representation of clustering results are carried out based on spectral lines and continuum,where these 13 types are characterized as regular spectra with low S/Ns,splicing problems,suspected galactic emission signals,contamination from city light and un-gregarious type ***,a preliminary analysis of their origins is made from the characteristics of the observational targets,contamination from the sky,and the working status of the *** results would be valuable for improving the overall data quality of large-scale spectral surveys.

关键词： methods data analysis-surveys-techniques spectroscopic-site testing-methods analytical