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Science China(Physics,Mechanics & Astronomy) 2013年第10期56卷 1833-1839页

作者： WANG FengFei zhang haotong LUO ALi BAI ZhongRui DU Bing ZHAO YongHeng National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

Spectrograph slit is conventionally used to enhance the spectral resolution ~md manage how much light can be allowed to enter spectrograph. The narrow slit provides a higher resolution but sacrifices efficiency of spectrograph and results in a low signal to noise ratio （S/N） spectra product. We take GuoShouJing telescope as an example and carry out a series of experiments to study how its 2/3 slit mode affects the precision of stellar radial velocity measurement and atmosphere parameters estimate. By transforming the resolution and adding a Gaussian White Noise to the extremely high quality spectra from the Sloan Digital Sky Survey, we generate synthetic stellar spectra of various brightness with different S/Ns. Comparing the measurements on these noise added spectra with the original high quality ones, we summarize the influences of the 2/3 slit mode on the meas- urement accuracy of stellar radial velocity and atmospheric parameters.

关键词： slit mode resolution stellar radial velocity atmosphere parameters spectrograph

A quasar possibly ejected from NGC4579

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Chinese Science Bulletin 2000年第10期45卷 886-888页

作者： ZHU Xingfen CHU Yaoquan WEI Jianyan zhang haotong HU Jingyao Center for Astrophysics University of Science and Technology of ChinaHefei 230026China Beijing Astronomical Observatory Chinese Academy of SciencesBeijing 100012China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China

With the 2.16 m telescope at Beijing Astronomical Observatory, it is identified that a compact X-ray source detected by ROSAT located in the vicinity of 5’ .9 from the LINER galaxy NGC4579 is a quasar with a redshift... 详细信息

关键词： quasar-galaxy-redshift.

Probing the Galactic Halo with RR Lyrae *** Radial Velocity Curve Templates of RRc Stars

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Research in Astronomy and Astrophysics 2024年第7期24卷 118-134页

作者： Yue Huang Min Fang Gaochao Liu Xianzhong Zheng Sarah Ann Bird Yang Huang Jianrong Shi Jiangtao Wang Huawei zhang Haijun Tian haotong zhang College of Science China Three Gorges UniversityYichang 443002China Center for Astronomy and Space Sciences China Three Gorges UniversityYichang 443002China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesBeijing 100101China Department of Astronomy School of PhysicsPeking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China

We present radial velocity(RV)curve templates of RR Lyrae first-overtone(RRc)stars constructed with the Mg I b triplet and Hαlines using time-domain Medium-Resolution Survey spectra of seven RRc stars from Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)Data Release ***,we derive the relation between the stellar RV curve amplitudes and g-band light curve amplitudes from Zwicky Transient Facility(ZTF)public *** those RRc stars without ZTF g-band light curves,we provide the conversions from the light curve amplitudes in ZTF r-and i-bands,Gaia G-band,and V-band from the All-Sky Automated Survey for Supernovae to those in ZTF *** validate our RV curve templates using the RRc star SV Scl and find the uncertainties of systemic RV are less than 2.11 km s~(-1)and 6.08 km s~(-1)based on the Mg I b triplet and Hαlines,*** calculate the systemic RVs of 30 RRc stars using the RV curve templates constructed with the Mg I b triplet and Hαlines and find the systemic RVs are comparable with each *** RV curve template will be particularly useful for obtaining the systemic RV of RRc using the LAMOST spectroscopy.

关键词： stars variables RR Lyrae-Stars-techniques radial velocities

Fault Diagnosis of the LAMOST Fiber Positioner Based on a Long Short-term Memory(LSTM)Deep Neural Network

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Research in Astronomy and Astrophysics 2023年第12期23卷 81-95页

作者： Yihu Tang Yingfu Wang Shipeng Duan Jiadong Liang Zeyu Cai Zhigang Liu Hongzhuan Hu Jianping Wang Jiaru Chu Xiangqun Cui Yong zhang haotong zhang Zengxiang Zhou Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)has been in normal operation for more than 10 yr,and routine maintenance is performed on the fiber positioner every *** positioning accuracy of the fiber positioner directly affects the observation performance of LAMOST,and incorrect fiber positioner positioning accuracy will not only increase the interference probability of adjacent fiber positioners but also reduces the observation efficiency of *** present,during the manual maintenance process of the positioner,the fault cause of the positioner is determined and analyzed when the positioning accuracy does not meet the preset *** causes maintenance to take a long time,and the efficiency is *** quickly locate the fault cause of the positioner,the repeated positioning accuracy and open-loop calibration curve data of each positioner are obtained in this paper through the photographic measurement *** on a systematic analysis of the operational characteristics of the faulty positioner,the fault causes are *** training a deep learning model based on long short-term memory,the positioner fault causes can be quickly located to effectively improve the efficiency of positioner fault cause *** relevant data can also provide valuable information for annual routine maintenance methods and positioner designs in the *** method of using a deep learning model to analyze positioner operation failures introduced in this paper is also of general significance for the maintenance and design optimization of fiber positioners using a similar double-turn gear transmission system.

关键词： telescopes-techniques image processing-methods analytical-techniques spectroscopic

The nearest neutron star candidate in a binary revealed by optical time-domain surveys

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 184-202页

作者： Ling-Lin Zheng Mouyuan Sun Wei-Min Gu Tuan Yi Zhi-Xiang zhang Pei Wang Junfeng Wang Jianfeng Wu Shan-Shan Weng Song Wang Sen-Yu Qi Jia zhang Chun-Qian Li Jian-Rong Shi Yong Shao Xiang-Dong Li Jin-Bo Fu Fan Yang Zhongrui Bai Yu Bai haotong zhang Jifeng Liu Department of Astronomy Xiamen UniversityXiamen 361005China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Department of Physics Institute of Theoretical PhysicsNanjing Normal UniversityNanjing 210023China Yunnan Observatories Chinese Academy of SciencesKunming 650216China College of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 210023China

The near-Earth(within~100 pc)supernova explosions in the past several million years can cause the global deposition of radioactive elements(e.g.,60Fe)on *** remnants of such supernovae are too old to be easily *** is therefore of great interest to search for million-year-old near-Earth neutron stars or black holes,the products of ***,neutron stars and black holes are challenging to find even in our Solar neighbourhood if they are not radio pulsars or X-ray/γ-ray *** we report the discovery of one of the nearest(127.7±0.3 pc)neutron star candidates in a detached single-lined spectroscopic binary LAMOST J235456.73+335625.9(hereafter J2354).Utilizing the time-resolved ground-based spectroscopy and space photometry,we find that J2354 hosts an unseen compact object with M_(inv)being 1.4-1.6 M_(⊙).The follow-up Swift ultraviolet(UV)and X-ray observations suggest that the UV and X-ray emission is produced by the visible star rather than the compact ***,J2354 probably harbours a neutron star rather than a hot ultramassive white ***-hour exceptionally sensitive radio follow-up observations with Five-hundred-meter Aperture Spherical radio Telescope fail to reveal any pulsating radio signals at the 6σflux upper limit of 12.5μ***,the neutron star candidate in J2354 can only be revealed via our time-resolved ***,the distance between J2354 and our Earth can be as close as~50 pc around 2.5 million years(Myrs)ago,as revealed by the Gaia *** discovery demonstrates a promising way to unveil the hidden near-Earth neutron stars in binaries by exploring the optical time domain,thereby facilitating understanding of the metal-enrichment history in our Solar neighbourhood.

关键词： neutron stars binary stars stellar evolution

A New Fiber Detection Method for LAMOST Based on the Front-illuminated Method

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Research in Astronomy and Astrophysics 2022年第6期22卷 42-51页

作者： Ming Zhou Yong zhang Guanru Lv Jian Li Zengxiang Zhou Zhigang Liu Jianping Wang Zhongrui Bai Yuan Tian Mengxin Wang Shuqing Wang Hongzhuan Hu Chao Zhai Jiaru Chu Zhijie Han Mingxu Liu Yiqiao Dong Hailong Yuan Yongheng Zhao Yaoquan Chu haotong zhang Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China University of Science and Technology of China Hefei 230026China

The double revolving fiber positioning technology is one of the key technologies for the success of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST).The accuracy of fiber positioning will directly affect the observation efficiency of *** achieve higher fiber positioning accuracy,the original open-loop controlled fiber positioning system urgently needs to be upgraded into a closed-loop control *** fiber detection is the most important part of the closed-loop controlled fiber positioning *** back-illuminated detection method is usually used to detect the fiber position by directly detecting the light spot generated at the fiber end in the multi-fiber spectral *** this paper,we introduce a new method to measure the fiber position based on the image of the front-illuminated LAMOST focal *** front-illuminated image does not require lighting devices inside the spectrograph,and it could reduce the instability and light pollution in the spectrograph *** method measures the fiber position by fitting the profile of the fiber pinhole with a 2D Gaussian function.A series of tests show that the relative position measurement precision of the front-illuminated method is about 012,and the method could have the same accuracy as the back-illuminated method once the system bias is calibrated by a simple radial correction *** required fiber positioning accuracy of LAMOST is 04,and the new method satisfies the requirement of LAMOST fiber detection accuracy and could be used in the closed-loop fiber control system.

关键词： techniques image processing-methods data analysis-instrumentation detectors

Overview of the LAMOST survey in the first decade

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The Innovation 2022年第2期3卷 49-64页

作者： Hongliang Yan Haining Li Song Wang Weikai Zong Haibo Yuan Maosheng Xiang Yang Huang Jiwei Xie Subo Dong Hailong Yuan Shaolan Bi Yaoquan Chu Xiangqun Cui Licai Deng Jianning Fu Zhanwen Han Jinliang Hou Guoping Li Chao Liu Jifeng Liu Xiaowei Liu Ali Luo Jianrong Shi Xuebing Wu haotong zhang Gang Zhao Yongheng Zhao CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Max-Planck Institute for Astronomy Königstuhl69117HeidelbergGermany South-Western Institute for Astronomy Research Yunnan UniversityKunming 650500China School of Astronomy and Space Science Nanjing UniversityNanjing 210093China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing UniversityNanjing 210093China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China University of Science and Technology of China Hefei 230026China National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesCASBeijing 100101China WHU-NAOC Joint Center for Astronomy Wuhan UniversityWuhan 430072China Department of Astronomy School of PhysicsPeking UniversityBeijing 100871China

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST),also known as the Guoshoujing Telescope,is a major national scientific facility for astronomical research located in Xinglong,*** with a pilot survey in 2011,LAMOST has been surveying the night sky for more than 10 *** LAMOST survey covers various objects in the Universe,from normal stars to peculiar ones.

关键词： China survey surveying

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肽-钙螯合方式及吸收机制研究现状

食品工业科技 2024年第19期45卷 383-391页

作者：张昊彤周雪巍乔凯娜武惠敏杨瑞张玉玉食品科学与工程学院天津科技大学天津300457 中原食品实验室北京工商大学北京100048 中国商业联合会味科学重点实验室北京工商大学北京100048

钙是人体必需的常量元素之一,科学补钙对维持生命健康具有重要意义,具有良好钙结合能力和高生物利用度的肽-钙螯合物也备受关注。本文综述了肽-钙螯合物中钙与肽的结合位点、结合模式、分子间作用力等内容。通过阐明游离钙和螯合钙的吸... 详细信息

钙是人体必需的常量元素之一,科学补钙对维持生命健康具有重要意义,具有良好钙结合能力和高生物利用度的肽-钙螯合物也备受关注。本文综述了肽-钙螯合物中钙与肽的结合位点、结合模式、分子间作用力等内容。通过阐明游离钙和螯合钙的吸收途径,分析螯合钙易被肠道吸收的特点。肽-钙螯合物作为新型钙补充剂,来源丰富且生物利用度高,具有良好的经济开发价值和广阔的发展前景。在肽-钙螯合物的安全性、物理化学稳定性、消化稳定性以及螯合钙被肠道吸收后Ca^(2+)的释放机制等方面的研究需要继续开展。本文旨在为新型钙补充剂的开发提供思路。

关键词：钙肽-钙螯合物补钙制剂钙吸收

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恒星大气参数测量

天文研究与技术 2018年第3期15卷 257-265页

作者：袁海龙张彦霞张昊彤赵永恒中国科学院光学天文重点实验室(国家天文台) 北京100101

从恒星的研究意义谈起,介绍了恒星大气参数的基本概念及研究意义;阐述了恒星参数测量方法的分类:直接测量和间接测量。着重评述了间接测量方法,包括测光方法、红外流量方法、巴尔默线轮廓拟合、谱线比例方法、线指数方法、金属线诊断法... 详细信息

从恒星的研究意义谈起,介绍了恒星大气参数的基本概念及研究意义;阐述了恒星参数测量方法的分类:直接测量和间接测量。着重评述了间接测量方法,包括测光方法、红外流量方法、巴尔默线轮廓拟合、谱线比例方法、线指数方法、金属线诊断法、光谱模板拟合和机器学习方法等。指出在大型巡天数据中光谱模板拟合与机器学习方法的优势及其广泛应用。对于高分辨率光谱,金属线诊断仍然备受天文学家青睐;红外流量方法的测量结果常用来定标。

关键词：参数测量恒星光谱机器学习

The Jiao Tong University Spectroscopic Telescope Project

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Astronomical Techniques and Instruments 2024年第1期1卷 16-30页

作者： JUST Team Chengze Liu Ying Zu Fabo Feng Zhaoyu Li Yu Yu Hua Bai Xiangqun Cui Bozhong Gu Yizhou Gu Jiaxin Han Yonghui Hou Zhongwen Hu Hangxin Ji Yipeng Jing Wei Li Zhaoxiang Qi Xianyu Tan Cairang Tian Dehua Yang Xiangyan Yuan Chao Zhai Congcong zhang Jun zhang haotong zhang Pengjie zhang Yong zhang Yi Zhao Xianzhong Zheng Qingfeng Zhu Xiaohu Yang Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China Department of Astronomy School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China University of Chinese Academy of Sciences NanjingNanjing 211135China University of Chinese Academy of Sciences Beijing 101408China Lenghu Technology Innovation Industrial Park Management Committee Lenghu 817400China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Department of Astronomy University of Science and Technology of ChinaHefei 230026China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

The Jiao Tong University Spectroscopic Telescope(JUST)is a 4.4-meter f/6.0 segmented-mirror telescope dedicated to spectroscopic *** JUST primary mirror is composed of 18 hexagonal segments,each with a diameter of 1.1 *** provides two Nasmyth platforms for placing science *** Nasmyth focus fits a field of view of 10′and the other has an extended field of view of 1.2°with correction optics.A tertiary mirror is used to switch between the two Nasmyth *** will be installed at a site at Lenghu in Qinghai Province,China,and will conduct spectroscopic observations with three types of instruments to explore the dark universe,trace the dynamic universe,and search for exoplanets:(1)a multi-fiber(2000 fibers)medium-resolution spectrometer(R=4000-5000)to spectroscopically map galaxies and large-scale structure;(2)an integral field unit(IFU)array of 500 optical fibers and/or a long-slit spectrograph dedicated to fast follow-ups of transient sources for multi-messenger astronomy;(3)a high-resolution spectrometer(R~100000)designed to identify Jupiter analogs and Earth-like planets,with the capability to characterize the atmospheres of hot exoplanets.

关键词： Astronomical instrumentation Optical telescopes Large-scale structure of the universe Redshift surveys Time domain astronomy Exoplanet astronomy