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The FAST all sky HI survey(FASHI):The first release of catalog

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 112-133页

作者： Chuan-Peng Zhang Ming Zhu Peng Jiang Cheng Cheng Jing Wang Jie Wang Jin-Long Xu Xiao-Lan Liu Nai-Ping Yu Lei Qian Haiyang Yu mei ai Yingjie Jing Chen Xu Ziming Liu Xin Guan Chun Sun Qingliang Yang Menglin Huang Qiaoli Hao FAST Collaboration Guizhou Radio Astronomical Observatory Guizhou UniversityGuiyang 550000China National Astronomical Observatories Chinese Academy of Sciences(CAS)Beijing 100101China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesCASBeijing 100101China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

The FAST All Sky HI survey(FASHI)was designed to cover the entire sky observable by the Five-hundred-meter Aperture Spherical radio Telescope(FAST),spanning approximately 22000 square degrees of declination between-14°and+66°,and in the frequency range of 1050-1450 MHz,with the expectation of eventually detecting more than 100000 HI sources.Between August 2020 and June 2023,FASHI had covered more than 7600 square degrees,which is approximately 35%of the total sky observable by FAST.It has a median detection sensitivity of around 0.76 m Jy beam-1and a spectral line velocity resolution of~6.4 km s-1at a frequency of~1.4 GHz.As of now,a total of 41741 extragalactic HI sources have been detected in the frequency range 1305.5-1419.5 MHz,corresponding to a redshift limit of z■0.09.By cross-matching FASHI sources with the Siena Galaxy Atlas(SGA)and the Sloan Digital Sky Survey(SDSS)catalogs,we found that 16972(40.7%)sources have spectroscopic redshifts and 10975(26.3%)sources have only photometric redshifts.Most of the remaining 13794(33.0%)HI sources are located in the direction of the Galactic plane,making their optical counterparts difficult to identify due to high extinction or high contamination of Galactic stellar sources.Based on current survey results,the FASHI survey is an unprecedented blind extragalactic H I survey.It has higher spectral and spatial resolution and broader coverage than the Arecibo Legacy Fast ALFA Survey(ALFALFA).When completed,FASHI will provide the largest extragalactic HI catalog and an objective view of HI content and large-scale structure in the local universe.

关键词： surveys redshifts galaxies telescope radio lines HI line

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HiFAST:An HIdata calibration and imaging pipeline for FAST

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 182-199页

作者： Yingjie Jing Jie Wang Chen Xu Ziming Liu Qingze Chen Tiantian Liang Jinlong Xu Yixian Cao Jing Wang Huijie Hu Chuan-Peng Zhang Qi Guo Liang Gao mei ai Hengqian Gan Xuyang Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang Xu Kong Fujia Li Zerui Liu Li Shao Hengxing Pan Jun Pan Lei Qian Jinghai Sun Ningyu Tang Qingliang Yang Bo Zhang Zhiyu Zhang Ming Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 02206China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Guizhou Radio Astronomical Observatory Guizhou UniversityGuiyang 55000China Max Planck Institute for Extraterrestrial Physics Garching 85748Germany Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Institute of Computational Cosmology Department of PhysicsUniversity of DurhamDurham DHI 3LEUK CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Deep Space Exploration Laboratory/Department of Astronomy University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Astrophysics Department of PhysicsUniversity of OxfordOxford OX/3RHUK College of Earth Sciences Guilin University of TechnologyGuilin 541004China Department of Physics Anhui Normal UniversityWuhu 241002China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 20023China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas(HI)in the universe.We present HiFAST(https://hifast.***.io),a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of FAST.The pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data cubes.These modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their variants.With HiFAST,the root-mean-square(RMS)noises of the calibrated spectra from all 19 beams were only slightly(~5%)higher than the theoretical expectation.The results for the extended source M33 and the point sources are consistent with the results from Arecibo.The moment maps(0,1 and 2)of M33 agree well with the results from the Arecibo Galaxy Environment Survey(AGES)with a fractional difference of less than 10%.For a common sample of 221 sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA(ALFALFA)survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1)is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H?in the universe.

关键词： fractional luminous correction

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Pricing Guaranteed Minimum Death Benefits with Dollar Cost Averaging Under Time-changed Le′vy Models

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Acta Mathematicae Applicatae Sinica 2024年

作者： Jia-ming WANG mei-qiao ai Zhi-min ZHANG College of Mathematics and Statistics Chongqing University

In this paper, we propose an efficient and accurate method for pricing Guaranteed Minimum Death Benefit (GMDB) under time-changed Le′vy processes. Suppose that the GMDB payoff depends on a dollar cost averaging (DCA) style periodic investment, and the activity rate process in stochastic time change is modeled by a square-root process. We develop a recursive method to derive the closed form valuation formula by using the frame duality projection method. Numerical examples are reported for demonstrating the effectiveness of our approach and illustrating the interplay between contract parameters and the valuation.

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HiFAST:An H?data calibration and imaging pipeline for FAST

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Science China(Physics,Mechanics & Astronomy) 2024年第5期Mechanics & Astronomy) .卷 186-203页

作者： Yingjie Jing Jie Wang Chen Xu Ziming Liu Qingze Chen Tiantian Liang Jinlong Xu Yixian Cao Jing Wang Huijie Hu Chuan-Peng Zhang Qi Guo Liang Gao mei ai Hengqian Gan Xuyang Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang Xu Kong Fujia Li Zerui Liu Li Shao Hengxing Pan Jun Pan Lei Qian Jinghai Sun Ningyu Tang Qingliang Yang Bo Zhang Zhiyu Zhang Ming Zhu School of Astronomy and Space Science University of Science and Technology of China Astrophysics Department of PhysicsUniversity of Oxford College of Earth Sciences Guilin University of Technology Department of Physics Anhui Normal University School of Astronomy and Space Science Nanjing University Key Laboratory of Modern Astronomy and Astrophysics Nanjing University National Astronomical Observatories Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University School of Astronomy and Space Science University of Chinese Academy of Sciences Guizhou Radio Astronomical Observatory Guizhou University Max Planck Institute for Extraterrestrial Physics Kavli Institute for Astronomy and Astrophysics Peking University Institute of Computational Cosmology Department of PhysicsUniversity of Durham CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of Sciences Deep Space Exploration Laboratory/Department of Astronomy University of Science and Technology of China

The Five-hundred-meter Aperture Spherical radio Telescope（FAST） has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas（H?） in the universe.We present HiFAST（https://hifast.***.io）,a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of FAST.The pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data cubes.These modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their variants.With HiFAST,the root-mean-square（RMS） noises of the calibrated spectra from all 19 beams were only slightly（～5%） higher than the theoretical expectation.The results for the extended source M33 and the point sources are consistent with the results from Arecibo.The moment maps（0,1 and 2） of M33 agree well with the results from the Arecibo Galaxy Environment Survey（AGES） with a fractional difference of less than 10%.For a common sample of 221 sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA（ALFALFA） survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1) is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H? in the universe.

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Integrated HI emission in galaxy groups and clusters

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Research in Astronomy and Astrophysics 2017年第10期17卷 15-26页

作者： mei ai Ming Zhu Jian Fu National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences

The integrated HI emission from hierarchical structures such as groups and clusters of galax- ies can be detected by FAST at intermediate redshifts. Here we propose to use FAST to study the evolution of the global HI content of clusters and groups over cosmic time by measuring their integrated HI emissions. We use the Virgo Cluster as an example to estimate the detection limit of FAST, and have estimated the integration time to detect a Virgo type cluster at different redshifts （from z = 0.1 to z ---- 1.5）. We have also employed a semi-analytic model （SAM） to simulate the evolution of HI contents in galaxy clusters. Our simulations suggest that the HI mass of a Virgo-like cluster could be 2-3 times higher and the physical size could be more than 50% smaller when redshift increases from z = 0.3 to z = 1. Thus the integration time could be reduced significantly and gas rich clusters at intermediate redshifts can be detected by FAST in less than 2 hours of integration time. For the local Universe, we have also used SAM simulations to create mock catalogs of clusters to predict the outcomes from FAST all sky surveys. Comparing with the optically selected catalogs derived by cross matching the galaxy catalogs from the SDSS survey and the ALFALFA survey, we find that the HI mass distribution of the mock catalog with 20 s of integration time agrees well with that of observations. However, the mock catalog with 120 s of integration time predicts many more groups and clusters that contain a population of low mass HI galaxies not detected by the ALFALFA survey. A future deep HI blind sky survey with FAST would be able to test such prediction and set constraints on the numerical simulation models. The observational strategy and sample selections for future FAST observations of galaxy clusters at high redshifts are also discussed.

关键词： galaxy clusters -- neutral hydrogen （HI） -- galaxy evolution

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Extragalactic HⅠSurvey with FAST:First Look at the Pilot Survey Results

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Research in Astronomy and Astrophysics 2022年第6期22卷 215-233页

作者： Jiangang Kang Ming Zhu mei ai Haiyang Yu Chun Sun National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National FASTNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Beijing Normal University Beijing 100875China

We present the first data release of HⅠsources extracted from a pilot extragalactic survey using the Five-hundredmeter Aperture Spherical radio Telescope(FAST).We extracted sources from three-dimensional(3D)spectral data cubes datacubes to perform interactive searching and computing,yielding global parameters for each source,extending redshift ranges of HⅠemission up to z=0.04.A total of 544 extragalactic HⅠsources has been detected by the pilot FAST HⅠdrift scan survey covering part of the sky region in R.A.(R.A.orα)and decl.(decl.orδ)range 00^(h)47^(m)6.5;(2)61 sources with 5.1■S/N■6.5;(3)28 sources with relatively poor baselines;(4)33 sources that are partly masked by strong radio frequency interferences(RFIs).In addition,we find 16 HⅠsources that have not been matched with any counterparts in the existing galaxy catalogs.This data release can provide guidance for the future extragalactic HⅠsurvey with FAST.

关键词： galaxies formation-radio lines galaxies-surveys-galaxies distances and redshifts-radiation dynamics-galaxies evolution

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Properties of the UCHII region G25.4NW and its associated molecular cloud

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Research in Astronomy and Astrophysics 2013年第8期13卷 935-944页

作者： mei ai Ming Zhu Li Xiao Hong-Quan Su National Astronomical Observatories Chinese Academy of Sciences

Ultra compact HII （UCHII） G25.4NW is a bright IR source in the region of the inner Galaxy. New HI images from the Very Large Array Galactic Plane Survey show clear absorption features associated with the UCHII region up to 95 km s^-1, and there are no other absorptions up to the tangential velocity. This reveals that G25.4NW has a near-side distance of 5.7 kpc, and it is located in the region of the inner Galactic molecular ring. Using the new distance, the bolometric luminosity of G25.4NW is estimated as 105.6 L⊙, which corresponds to an 06 star. It contains 460 M⊙ of ionized gas. A high-resolution ^13CO image from the Galactic Ring Survey reveals that G25.4NW is part of a more extended star-forming complex with about 104 M⊙ of molecular gas.

关键词： radiation mechanisms： thermal - ISM： atoms - ISM： HII regions - ISM： molecules

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医院信息管理系统在医学检验中的应用探究

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科学与信息化 2024年第7期 160-162页

作者：李爱梅山东省烟台市福山区人民医院山东烟台 265500

随着信息技术的不断发展,信息管理系统在医学检验中的应用越来越广泛.医学检验的数据量大、种类多,需要高效的信息管理系统来支持.信息管理系统可以在医学检验的各个环节中发挥重要作用.文章首先分析了信息管理系统在医学检验中的应用... 详细信息

随着信息技术的不断发展,信息管理系统在医学检验中的应用越来越广泛.医学检验的数据量大、种类多,需要高效的信息管理系统来支持.信息管理系统可以在医学检验的各个环节中发挥重要作用.文章首先分析了信息管理系统在医学检验中的应用的意义,其次针对医院信息管理系统在医学检验中应用功能模块进行了分析.

关键词：信息管理系统医学检验应用

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共同富裕背景下南通提高劳动报酬占GDP比重的可行路径

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南通职业大学学报 2024年第1期38卷 5-9,36页

作者：赵芹刘爱梅江苏工程职业技术学院马克思主义学院江苏南通226006 山东社会科学院农村发展研究所济南250002

提高劳动报酬占GDP比重是实现共同富裕的关键指标之一,对经济社会发展具有重要意义。南通不仅具备提高劳动报酬占GDP比重的基础,也面临紧迫的现实需求。为此,实证分析了南通市提高劳动报酬占GDP比重面临的负面影响因素,主要包括出口贸... 详细信息

提高劳动报酬占GDP比重是实现共同富裕的关键指标之一,对经济社会发展具有重要意义。南通不仅具备提高劳动报酬占GDP比重的基础,也面临紧迫的现实需求。为此,实证分析了南通市提高劳动报酬占GDP比重面临的负面影响因素,主要包括出口贸易额下滑、新质生产力尚处发动阶段、地区优势挖掘不充分等经济发展层面的影响因素,以及税收制度部分规定对资本的友好度大于对劳动力的友好度等分配机制层面的问题。进而提出了相应的改进建议:通过挽留产业链、加快新质生产力代谢、充分整合旅游资源、提升劳动者技能素养和加快乡村数字化赋能等多渠道提升经济总量,通过打造低收入群体友好型城市、优化税收调控及提高工资中劳动要素价值占比等措施,进一步改善分配机制,以提高劳动报酬占GDP比重,推动共同富裕目标的实现。

关键词：劳动报酬共同富裕南通分配机制新质生产力占GDP比重

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领导与员工的超连接匹配对工作绩效的影响及其机制

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管理科学学报 2024年第1期27卷 61-74页

作者：李爱梅王海侠刘培陈晨马捷秦昕暨南大学管理学院广州510632 暨南大学新闻与传播学院广州510632 中山大学旅游学院珠海519082 中山大学管理学院广州510275

数字技术在企业的创新应用正在重构传统企业管理学理论与方法.工作中片刻不离手机和笔记本等多种设备的“超连接”成为常态.已有研究关注了互联网超连接对个体心理和行为的一系列消极影响,却忽略了数字技术赋能下的领导与员工超连接对... 详细信息

数字技术在企业的创新应用正在重构传统企业管理学理论与方法.工作中片刻不离手机和笔记本等多种设备的“超连接”成为常态.已有研究关注了互联网超连接对个体心理和行为的一系列消极影响,却忽略了数字技术赋能下的领导与员工超连接对工作绩效的潜在积极影响.本文基于平衡理论,连续三个月跟踪调查了343份领导与员工的配对样本,结果发现:领导与员工之间的超连接越匹配,员工自主性越高,工作目标进展越快,工作绩效显著增加.进一步发现,当领导与员工同处于高超连接时,员工的自主性高,工作目标进展和工作绩效最佳;而在“员工低—领导高”的不匹配模式下,员工的自主性和工作进展都低.本文从匹配视角探究领导与员工超连接模式对工作绩效的积极后效,为数字技术赋能组织管理的工作模式提供了更加全面和均衡的分析视角,同时也为实现领导与员工的工作模式匹配、协同推进工作绩效提供实践指导.

关键词：互联网超连接匹配员工自主性工作目标进展工作绩效

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