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Moon night sky brightness simulation for the Xinglong station

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Research in Astronomy and Astrophysics 2013年第10期13卷 1255-1268页

作者： Song Yao Hao-Tong Zhang hai-long yuan Yong-Heng Zhao Yi-Qiao Dong Zhong-Rui Bai Li-Cai Deng Ya-Juan Lei Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

Using a sky brightness monitor at the Xinglong station of National Astronomical Observatories,Chinese Academy of Sciences,we collected data from22 dark clear nights and 90 moon *** first measured the sky brightness variation with time for dark nights and found a clear correlation between sky brightness and human *** with a modified sky brightness model of moon nights and data from these nights,we derived the typical value for several important parameters in the *** these results,we calculated the sky brightness distribution under a given moon condition for the Xinglong ***,we simulated the sky brightness distribution of a moon night for a telescope with a 5 field of view（such as LAMOST）.These simulations will be helpful for determining the limiting magnitude and exposure time,as well as planning the survey for LAMOST during moon nights.

关键词： Moon scattering site testing telescopes

Sky subtraction for LAMOST

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Research in Astronomy and Astrophysics 2017年第9期17卷 25-38页

作者： Zhong-Rui Bai Hao-Tong Zhang hai-long yuan Guang-Wei Li Jian-Jun Chen Ya-Juan Lei Hui-Qin Yang Yi-Qiao Dong Gang Wang Yong-Heng Zhao 1 University of Chinese Academy of Sciences Beijing 100049China Key Lab for Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China

Sky subtraction is a key technique in data reduction of multi-fiber spectra. Knowledge of characteristics related to the instrument is necessary to determine the method adopted in sky subtraction. In this study, we describe the sky subtraction method designed for the Large sky Area Multi-Object fiber Spectroscopic Telescope （LAMOST） survey. The method has been integrated into the LAMOST 2D Pipeline v2.6 and applied to data from LAMOST DR3 and later. For LAMOST, calibration using sky emission lines is used to alleviate the position-dependent （and thus time-dependent） ,-~ 4% fiber throughput uncertainty and small wavelength instability （0.1/~） during observation. Sky subtraction using principal component analysis （PCA） further reduces 25% of the sky line residual from OH fines in the red part of LAMOST spectra after the master sky spectrum, which is derived from a B-spline fit of 20 sky fibers in each spectrograph. Using this approach, values are adjusted by a sky emission line and subtracted from each fiber. Further analysis shows that our wavelength calibration accuracy is about 4.5 km s-1, and the averages of residuals after sky subtraction are about 3% for sky emission lines and 3% for the continuum region. The relative sky subtraction residuals vary with moonlight background brightness, and can reach as low as 1.5% for regions that have sky emission lines during a dark night. Tests on F stars with both similar sky emission line strength and similar object continuum intensity show that the sky emission line residual of LAMOST is smaller than that of the SDSS survey.

关键词： techniques: spectroscopic -- methods data analysis -- instrumentation spectrographs

Candidate members of the Pal 5, GD-1, Cetus Polar and Orphan tidal stellar halo streams from SDSS DR9, LAMOST DR3 and APOGEE catalogs

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Research in Astronomy and Astrophysics 2017年第6期17卷 117-128页

作者： Guang-Wei Li Brian Yanny Hao-Tong Zhang Zong-Rui Bai Yue Wu Yi-Qiao Dong Ya-Juan Lei hai-long yuan Yong-Hui Hou Yue-Fei Wang Yong Zhang Key Lab for Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Fermi National Accelerator Laboratory Batavia IL 60510 USA Nanjing Institute of Astronomical Optics & Technology National Astronomical Observatories Chinese Academy of Sciences Nanjing 210042 China

We present candidate members of the Pal 5, GD-1, Cetus Polar and Orphan tidal stellar streams found in LAMOST DR3, SDSS DR9 and APOGEE catalogs. In LAMOST DR3, we find 20, 4 and 24 high confidence candidates of tidal streams GD-1, Cetus Polar and Orphan respectively. We also list 59, 118 and 10 high confidence candidates of tidal streams Cetus Polar, Orphan and Pal 5, respectively from the SDSS DR9 spectroscopic catalog. Furthermore, we find seven high confidence candidates of the Pal 5 tidal stream in the APOGEE data. Compared with SDSS, the new candidates from LAMOST DR3 are brighter, so that together, more of the color-magnitude diagram, including the giant branch, can be explored. Analysis of the SDSS data shows that there are three metallicity peaks associated with the Orphan stream which also exhibit some spatial separation. The LAMOST data confirm multiple metallicities in this stream. The metallicity, given by the higher resolution APOGEE instrument, of the Pal 5 tidal stream is [Fe/H] ,- -1.2, higher than that given earlier by SDSS spectra. Many previously unidentified stream members are tabulated here for the first time, along with existing members, allowing future researchers to further constrain the orbits of these objects as they move within the Galaxy＇s dark matter potential.

关键词： Galaxy structure general stream - Galaxy structure individual (GD-1, Orphan, Cetus, Pal 5)

LAMOST/HRS spectroscopic analysis of two new Li-rich giants

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Research in Astronomy and Astrophysics 2021年第1期21卷 198-206页

作者： Ze-Ming Zhou Jian-Rong Shi Hong-Liang Yan Yong-Hui Hou Kai Zhang Qi Gao Xiao-Dong Xu hai-long yuan Yu-Tao Zhou Kaike Pan Zi-Ye Sang Yong-Heng Zhao CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of ScienceBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China Department of Astronomy Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Apache Point Observatory SunspotNew Mexico 88349USA Astronomy Department New Mexico State UniversityLas CrucesNew Mexico 88003USA

Two Li-rich candidates,TYC 1338-1410-1 and TYC 2825-596-1,were observed by the new high-resolution echelle spectrograph,LAMOST/*** on their high-resolution and high-signal-tonoise ratio(SNR)spectra,we derived stellar parameters and abundances of 14 important elements for the two *** stellar parameters and lithium abundances indicate that they are Li-rich K-type giants,and having A(Li)NLTE and 2.91 dex,*** analysis suggests that TYC 1338-1410-1 is probably a red giant branch(RGB)star at the bump stage,while TYC 2825-596-1 is most likely to be a core helium-burning red clump(RC)*** line profiles of both spectra indicate that the two Li-rich giants are slow rotators and do not show infrared(IR)*** conclude that engulfment is not the lithium enrichment mechanism for either *** enriched lithium of TYC 1338-1410-1 could be created via the Cameron-Fowler mechanism,while the lithium excess in TYC 2825-596-1 could be associated with either non-canonical mixing processes or He-flash.

关键词： stars:fundamental parameters stars:late-type stars:low-mass stars:abundances stars:chemically peculiar

A sample of galaxy pairs identified from the LAMOST spectral survey and the Sloan Digital Sky Survey

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Research in Astronomy and Astrophysics 2016年第3期16卷 63-72页

作者： Shi-Yin Shen Maria Argudo-Femandez Li Chen Xiao-Yan Chen Shuai Feng Jin-Liang Hou Yong-Hui Hou Peng Jiang Yi-Peng Jing Xu Kong A-Li Luo Zhi-Jian Luo Zheng-Yi Shao Ting-Gui Wang Wen-Ting Wang Yue-Fei Wang Hong Wu Xue-Bing Wu hai-Feng Yang Ming Yang Fang-Ting yuan hai-long yuan Hao-Tong Zhang Jian-Nan Zhang Yong Zhang Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China Key Lab for Astrophysics Shanghai 200234China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China University of Chinese Academy of Sciences Beijing 100049China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China University of Science and Technology of China Hefei 230026China Department of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Institute for Computational Cosmology University of DurhamSouth RoadDurhamDH1 3LEUK Department of Astronomy Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

A small fraction （〈 10%） of the SDSS main galaxy （MG） sample has not been targeted with spectroscopy due to the effect of fiber collisions. These galaxies have been compiled into the input catalog of the LAMOST ExtraGAlactic Surveys and named the complementary galaxy sample. In this paper, we introduce this project and status of the spectroscopies associated with the complementary galaxies in the first two years of the LAMOST spectral survey （till Sep. of 2014）. Moreover, we present a sample of 1102 galaxy pairs identified from the LAMOST complementary galaxies and SDSS MGs, which are defined as two members that have a projected distance smaller than 100 h^-01kpc and a recessional velocity difference smaller than 500 km s-1. Compared with galaxy pairs that are only selected from SDSS, the LAMOST- SDSS pairs have the advantages of not being biased toward large separations and therefore act as a useful supplement in statistical studies of galaxy interaction and galaxy merging.

关键词： galaxies: interactions -- galaxies: groups: general

Study on Integral Dissolution Model Based on Biological Potency for Compound Chinese Materia Medica

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Chinese Herbal Medicines 2015年第2期7卷 143-149页

作者： Yun-zhi Xiao yuan Dong Chao-yong Liu Li-hong Zhang Chao Yu Lu Wan Jin Han hai-long yuan Department of Pharmacy 302 Military Hospital School of Pharmacy Chengdu University of Traditional Chinese Medicine

Objective To investigate the integral dissolution model based on biological potency in order to evaluate the dissolution of Compound Chinese materia medica（CCMM） in vitro. Methods The contents of paeoniflorin, phillyrin, ginsenoside Rg1, and adenosine of ten batches of Compound Biejia Ruangan Tablet（CBRT） were determined at different times. The self-defined weighting coefficient based on the contents has been created to establish the integral dissolution model. In addition, the biological potency of CBRT was measured by MTT assay. Then, the f2 similar factor was used to evaluate the similarity of the batches. Results Compared with batch a, some batches’ f2 values of paeoniflorin and adenosine were less than 50, while f2 values of ginsenoside Rg1, phillyrin, and integral component were more than 50. Likewise, ginsenoside Rg1, phillyrin, and integral component were all in good correlation with biological dissolution. Conclusion The results of the integral dissolution based on biological test of CBRT demonstrate that the bioassay method may be a promising supplement for its quality evaluation.

关键词： biological potency Compound Biejia Ruangan Tablet integral dissolution similarity factors

The galaxy luminosity function in the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap

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Research in Astronomy and Astrophysics 2019年第8期19卷 69-80页

作者： Pin-Song Zhao Hong Wu Cong Kevin Xu Ming Yang Fan Yang Yi-Nan Zhu Man I Lam Jun-Jie Jin hai-long yuan Hao-Tong Zhang Shi-Yin Shen Jian-Rong Shi A-Li Luo Xue-Bing Wu Yong-Heng Zhao Yi-Peng Jing Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing100049China Chinese Academy of Sciences South America Center for Astronomy China-Chile Joint Center for AstronomyCamino El Observatorio1515Las CondesSantiagoChile IAASARS National Observatory of AthensVas.Pavlou&I.MetaxaPenteli15236Greece Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy ofSciencesShanghai200030China Department of Astronomy School of PhysicsPeking UniversityBeijing100871China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai200240China

We present optical luminosity functions(LFs) of galaxies in the0.1 g,0.1 r,0.1 i bands, calculated using data in40 deg2 sky area of the LAMOST Complete Spectroscopic Survey of Pointing Area(LaCoSSPAr) in the Southern Galactic Cap. Redshifts for galaxies brighter than r = 18.1 were obtained mainly with LAMOST. In each band, LFs derived using both parametric and non-parametric maximum likelihood methods agree well with each other. In the0.1 r band, our fitting parameters of the Schechter function are φ*=(1.65 ± 0.36) × 10-2 h3 Mpc-3, M*=-20.69 ± 0.06 mag and α =-1.12 ± 0.08,which agree with previous studies. Separate LFs are also derived for emission line galaxies and absorption line galaxies. The LFs of absorption line galaxies show a dip at0.1 r 18.5 and can be fitted well by a double-Gaussian function, suggesting a bimodality in passive galaxies.

关键词： galaxies:luminosity function,mass function galaxies:statistics galaxies:distances and redshifts

The first data release of LAMOST low-resolution single-epoch spectra

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Research in Astronomy and Astrophysics 2021年第10期21卷 73-85页

作者： Zhong-Rui Bai Hao-Tong Zhang hai-long yuan Dong-Wei Fan Bo-Liang He Ya-Juan Lei Yi-Qiao Dong Si-Cheng Yu Yong-Heng Zhao Yong Zhang Yong-Hui Hou Yao-Quan Chu CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesBeijing 100101China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China National Astronomical Data Center Beijing 100101China Nanjing Institute of Astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China University of Science and Technology of China Hefei 230026China

LAMOST Data Release 5,covering 17000 deg^(2) from-10°to 80°in declination,contains 9 million co-added low-resolution spectra of celestial objects,each spectrum combined from repeat exposure of two to tens of times during Oct 2011 to Jun *** this paper,we present the spectra of individual exposures for all the objects in LAMOST Data Release *** each spectrum,the equivalent width of 60lines from 11 different elements are calculated with a new method combining the actual line core and fitted line *** stars earlier than F type,the Balmer lines are fitted with both emission and absorption profiles once two components are *** velocity of each individual exposure is measured by minimizing χ^(2) between the spectrum and its best *** database for equivalent widths of spectral lines and radial velocities of individual spectra are available *** velocity uncertainties with different stellar type and signal-to-noise ratio are quantified by comparing different exposure of the same *** notice that the radial velocity uncertainty depends on the time lag between *** stars observed in the same day and with signal-to-noise ratio higher than 20,the radial velocity uncertainty is below 5 km s^(-1),and increases to 10 km s^(-1) for stars observed in different nights.

关键词： surveys stars:general methods:data analysis

Formulation and evaluation of fast dissolving sublingual films of methylphenidate hydrochloride

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Formulation and evaluation of fast dissolving sublingual fil...