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Research in Astronomy and Astrophysics 2021年第3期21卷 235-242页

作者： hai-bo yuan Ding-Shan Deng Yang Sun Department of Astronomy Beijing Normal UniversityBeijing 100875China

The Chinese Space Station Telescope(CSST)spectroscopic survey aims to deliver high-quality low-resolution(R>200)slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag,distributed within a large survey area(17500 deg2)and covering a wide wavelength range(255-1000 nm by three bands GU,GV,and GI).As slitless spectroscopy precludes the usage of wavelength calibration lamps,wavelength calibration is one of the most challenging issues in the reduction of slitless spectra,yet it plays a key role in measuring precise radial velocities of stars and redshifts of *** this work,we propose a star-based method that can monitor and correct for possible errors in the CSST wavelength calibration using normal scientific observations,taking advantage of the facts that(ⅰ)there are about ten million stars with reliable radial velocities now available thanks to spectroscopic surveys like LAMOST,(ⅱ)the large field of view of CSST enables efficient observations of such stars in a short period of time,and(ⅲ)radial velocities of such stars can be reliably measured using only a narrow segment of CSST *** demonstrate that it is possible to achieve a wavelength calibration precision of a few km s^(-1) for the GU band,and about 10 to 20 kms^(-1) for the GV and GI bands,with only a few hundred velocity standard *** of the method to other surveys are also discussed.

关键词： methods:data analysis methods:statistical techniques:spectroscopic techniques:radial velocities stars:fundamental parameters stars:kinematics and dynamics

Precision of the Chinese Space Station Telescope(CSST)stellar radial velocities

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Research in Astronomy and Astrophysics 2021年第4期21卷 207-215页

作者： Yang Sun Ding-Shan Deng hai-bo yuan Department of Astronomy Beijing Normal UniversityBeijing 100875China

The Chinese Space Station Telescope(CSST)spectroscopic survey plans to deliver high-quality low-resolution(R>200)slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag,covering a large survey area(17500 deg^(2))and a wide wavelength range(255-1000 nm by three bands GU,GV,and GI).In this work,we use empirical spectra of the Next Generation Spectral Library to simulate the CSST stellar spectra at R=250,and investigate their capabilities in measuring radial *** find that velocity uncertainties depend strongly on effective temperature,weakly on metallicity for only FGK stars,and hardly on surface *** is possible to deliver stellar radial velocities to a precision of about 3 kms^(-1)for AFGKM stars,and about 10 km s^(-1)for OB stars,at signal-to-noise ratio(SNR)of *** uncertainties using single GU/GV/GI band spectra are also *** the same SNR,the GU band performs best,the GV band the second best,and then the GI *** effects of spectral normalization and the imperfect template on velocity measurements are investigated and found to be very *** uncertainties caused by wavelength calibration are considered and found to be *** the possible precision of radial velocities,the CSST spectroscopic survey can enable interesting science such as searching for hyper-velocity *** of our results are also discussed.

关键词： methods:data analysis methods:statistical stars:fundamental parameters stars:kinematics and dynamics

The assembly of the Milky Way and its satellite galaxies

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Research in Astronomy and Astrophysics 2012年第8期12卷 1021-1043页

作者： Martin C. Smith Sakurako Okamoto hai-bo yuan Xiao-Wei Liu Kavli Institute for Astronomy and Astrophysics Peking University Beijing 100871 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China LAMOST Fellow Department of Astronomy Peking University Beijing 100871 China

In recent years it has become clear that the Milky Way is an important test- ing ground for theories of galaxy formation. Much of this growth has been driven by large surveys, both photometric and spectroscopic, which are producing vast and rich catalogs of data. Through the analysis of these data sets we can gain new and detailed insights into the physical processes which shaped the Milky Way＇s evolution. This review will discuss a number of these developments, first focusing on the disk of the Milky Way, and then looking at its satellite population. The importance of surveys has not gone unnoticed by the Chinese astronomy community and in the final section we discuss a number of Chinese projects that are set to play a key role in the development of this field.

关键词： Galaxy: structure -- Galaxy: evolution -- Galaxy: kinematics and dy-namics -- Galaxy: disk -- galaxies: dwarf-- surveys

Atmospheric extinction coefficients and night sky brightness at the Xuyi Observation Station

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Research in Astronomy and Astrophysics 2013年第4期13卷 490-500页

作者： Hui-Hua Zhang Xiao-Wei Liu hai-bo yuan hai-Bin Zhao Jin-Sheng Yao Hua-Wei Zhang Mao-Sheng Xiang Department of Astronomy Peking University Kavli Institute for Astronomy and Astrophysics Peking University Purple Mountain Observatory Chinese Academy of Sciences

We present measurements of the optical broadband atmospheric extinction coefficients and the night sky brightness at the Xuyi Observation Station of Purple Mountain Observatory. The measurements are based on CCD imaging data taken in the Sloan Digital Sky Survey＇s g, r and i bands with the Xuyi 1.04/1.20m Schmidt Telescope for the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticenter （XSTPS-GAC）, the photometric part of the Digital Sky Survey of the Galactic Anti-center （DSS-GAC）. The data were collected during more than 140 winter nights from 2009 to 2011. We find that the atmospheric extinction coefficients for the g, r and i bands are 0.69, 0.55 and 0.38 mag/airmass, respectively, based on observations taken on several photometric nights. The night sky brightness determined from images with good quality has median values of 21.7, 20.8 and 20.0 mag arcsec-2 and reaches 22.1, 21.2 and 20.4mag arcsec-2 under the best observing conditions for the g, r and i bands, respectively. The relatively large extinction coefficients compared with other good astronomical observing sites are mainly due to the relatively low elevation （i.e. 180 m） and high humidity at the station.

关键词： techniques: astronomical observing sites -- atmospheric extinction co- efficients -- night sky brightness

Astrometric calibration of the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center(XSTPS-GAC)

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Research in Astronomy and Astrophysics 2014年第4期14卷 456-470页

作者： Hui-Hua Zhang Xiao-Wei Liu hai-bo yuan hai-Bin Zhao Jin-Sheng Yao Hua-Wei Zhang Mao-Sheng Xiang Yang Huang Department of Astronomy Peking University Kavli Institute for Astronomy and Astrophysics Peking University Purple Mountain Observatory Chinese Academy of Sciences

Abstract We present astrometric calibration of the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center （XSTPS-GAC）. XSTPS-GAC is the photometric part of the Digital Sky Survey of the Galactic Anti-center （DSS-GAC）, which is a photometric and spectroscopic sky survey, in combination with LAMOST. In order to select an astrometric reference catalog, we made comparisons between the four widely used astrometric catalogs, GSC2.3, USNO-B1.0, UCAC3 and PPMXL. PPMXL shows relatively small systematic errors in positions and more homogeneous proper motion distributions toward the Galactic Anti-center （GAC）, and was selected as the reference catalog. Based on the high quality and bright reference stars that were picked out from PPMXL, we performed a 4th-order polynomial fitting in image units, to construct the transformation relation between coordinates used by XSTPS-GAC and standard coordinates, and to simultaneously correct the image distortions in the CCD. Then we applied the derived relation to all sources to obtain their mean celestial coordinates based on the Intemational Celestial Reference System. For bright point sources with r 〈 17.0 mag, the accuracy of astrometric calibration could reach about 80 mas for each of the g, r, i bands, with systematic errors being less than 10 mas. But for the faint sources at the brightness limit of the survey, which was r - 19.0 mag, the accuracy can still reach 200 mas. After combining all observations, the final weighted average coordinates could reach an accuracy of less than 70 mas for bright stars. For faint stars, the rms residuals of weighted coordinates decrease to -110 mas. The final combined XSTPS-GAC coordinates show a good consistency with the Sloan Digital Sky Survey.

关键词： astrometry -- methods: data analysis -- surveys

The Stellar Abundances and Galactic Evolution Survey:Photonic Passbands and Extinction Coefficients for the u and v Bands

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Research in Astronomy and Astrophysics 2022年第10期22卷 39-48页

作者： Ke-Feng Tan Gang Zhao Zhou Fan Wei Wang hai-bo yuan Jie Zheng Chun Li Nan Song Jing-Kun Zhao CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 10049China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Astronomy Beijing Normal UniversityBeijing 100875China China Science and Technology Museum Beijing 100101China

The Stellar Abundances and Galactic Evolution Survey(SAGES)is a multi-band photometric survey focused on estimation of stellar atmospheric parameters and interstellar *** this paper we have derived photonic passbands for the intermediate-band u and v filters of the SAGES photometric *** derived photonic passbands have been compared with those of the u and v filters of the Stromgren and SkyMapper *** photometry based on the derived photonic passbands could reproduce the observations very *** have also derived observed,model-free extinction coefficients for the SAGES u and v bands(as well as the Pan-STARRS grizy bands)using the“standard pair”*** derived reddening coefficients have been compared with those predicted by the extinction *** of reddening coefficients with effective temperatures and color excesses of B–V given by Schlegel et al.(E(B-V)_(SFD))have been *** obvious trends or significant variations with effective temperatures have been found,but reddening coefficients for all the colors exhibit declining trends with increasing E(B-V)_(SFD),with typical relative variations of twenty-some percent from E(B-V)_(SFD)~0 to 1.

关键词： stars general-(ISM:)dust-extinction-techniques photometric

Stellar loci *** giant stars

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Research in Astronomy and Astrophysics 2021年第12期21卷 550-562页

作者： Ruo-Yi Zhang hai-bo yuan Xiao-Wei Liu Mao-Sheng Xiang Yang Huang Bing-Qiu Chen Department of Astronomy Beijing Normal UniversityBeijing 100875China South-Western Institute for Astronomy Research Yunnan UniversityKunming 650500China Max-Planck Institute for Astronomy KonigstuhlD-69117HeidelbergGermany

In the fourth paper of this series,we present the metallicity-dependent Sloan Digital Sky Survey(SDSS)stellar color loci of red giant stars,using a spectroscopic sample of red giants in the SDSS Stripe82 *** stars span a range of 0.55-1.2 mag in color g-i,-0.3--2.5 in metallicity[Fe/H],and have values of surface gravity log g smaller than 3.5 *** in the case of main-sequence(MS)stars,the intrinsic widths of loci of red giants are also found to be quite narrow,a few mmag at *** are however systematic differences between the metallicity-dependent stellar loci of red giants and MS *** colors of red giants are less sensitive to metallicity than those of MS *** good photometry,photometric metallicities of red giants can be reliably determined by fitting the u-g,g-r,r-i,and i-z colors simultaneously to an accuracy of 0.2-0.25 dex,comparable to the precision achievable with low-resolution spectroscopy for a signal-to-noise ratio of *** comparing fitting results to the stellar loci of red giants and MS stars,we propose a new technique to discriminate between red giants and MS stars based on the SDSS *** technique achieves completeness of~70 per cent and efficiency of~80 per cent in selecting metal-poor red giant stars of[Fe/H]≤-*** thus provides an important tool to probe the structure and assemblage history of the Galactic halo using red giant stars.

关键词： methods:data analysis stars:fundamental parameters stars:general surveys

Simulation of a Marine Controllable Phase-Compounding Excitation System

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International Journal of Plant Engineering and Management 2007年第4期12卷 227-233页

作者： GAO hai-bo WU Fu-yuan CHEN Hui School of Energy and Power Engineering Wuhan University of Technology Wuhan 430063 P. R. China

We first established the mathematical model of a marine synchronous generator and its controllable phase-compounding excitation system, and then made a simulation sketch with Saber simulation software. According to ＂Regulations for the Construction and Classification of Ocean-going Steel Ships＂ of the China Classification Society （CCS） , some experiments are designed to verify the property of the simulation model. Some experiments, such as free start, load sudden on and off, have been CO is mpleted, and the result indicates that the model conforms to the requirements of the rules very well. It qualified for a marine electrical propulsion simulation.

关键词： synchronous generator excitation system Saber simulation

The LAMOST survey of background quasars in the vicinity of M31 and M33–Ⅲ.results from the 2013 regular survey

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Research in Astronomy and Astrophysics 2015年第8期15卷 1438-1448页

作者： Zhi-Ying Huo Xiao-Wei Liu Mao-Sheng Xiang Jian-Rong Shi hai-bo yuan Yang Huang Yong Zhang Yong-Hui Hou Yue-Fei Wang Ming Yang National Astronomical Observatories Chinese Academy of Sciences Department of Astronomy Peking University Kavli Institute for Astronomy and Astrophysics Peking University Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences

In this work, we report new quasars discovered in fields in the vicinity of the Andromeda（M31） and Triangulum（M33） galaxies with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST, also called the Guo Shou Jing Telescope） during the 2013 observational season, the second year of the regular survey. In total, 1330 new quasars are discovered in an area of ～133 deg2 around M31and M33. With i magnitudes ranging from 14.79 to 20.0 and redshifts from 0.08 to4.85, the 1330 new quasars represent a significant increase in the number of identified quasars in fields in the vicinity of M31 and M33. Up to now, there have been a total of 1870 quasars discovered by LAMOST in this area. The much enlarged sample of known quasars in this area can potentially be utilized to construct a precise astrometric reference frame for the measurement of minute proper motions of M31, M33 and their associated substructures, which are vital for understanding the formation and evolution of M31, M33 and the Local Group of galaxies. Moreover, in the sample,there are a total of 45, 98 and 225 quasars with i magnitudes brighter than 17.0, 17.5and 18.0 respectively. In the aforementioned brightness bins, 15, 35 and 84 quasars are reported here for the first time, and 6, 21 and 81 are reported in our pervious work. In addition, 0, 1 and 6 are from the Sloan Digital Sky Survey and 24, 41 and 54 are from the NED database. These bright quasars provide an invaluable sample to study the kinematics and chemistry of the interstellar/intergalactic medium of the Local Group.

关键词： galaxies: individual(M31 M33)—quasars: general—quasars: emission lines

Galactic halo age estimated from LAMOST DR4 and Gaia DR1

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Research in Astronomy and Astrophysics 2019年第1期19卷 87-94页

作者： Jin-Cheng Guo Hua-Wei Zhang Yang Huang Xiao-Wei Liu Ji-Feng Liu Mao-Sheng Xiang Bing-Qiu Chen hai-bo yuan Zhi-Jia Tian Zhi-Ying Huo Chun Wang Department of Astronomy Peking University Kavli Institute for Astronomy and Astrophysics Peking University Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences South-Western Institute for Astronomy Research Yunnan University Department of Astronomy Beijing Normal University

The stellar halo is one of the major components in the Milky Way. Research on its age can provide critical constraints on the origin of the stellar halo and further on the formation of our *** far, different approaches and samples have been used to estimate the age of the Galactic halo. In our previous paper, we carefully selected 63 field halo turn-off stars within 1 kpc from the literature using a kinematic approach, then estimated the age of the halo. In this following work, we not only update the data from LAMOST DR4 and Gaia DR1, but also try a different method to select a clean halo sample by combining the metallicity and orbital parameters. Then we compare this halo turn-off sample with the GARSTEC model in the B-V vs. metallicity plane. After Monte Carlo simulations are performed, the age is estimated to be 10.5±1.4 Gyr, highly consistent with our previous result and other studies. However,due to the limited common sources between LAMOST DR4 and Gaia DR1, the final sample in this paper is still quite small. The estimated age will be more robust with the much larger Gaia DR2.

关键词： galaxies:halos Galaxy:evolution stars:kinematics and dynamics