在SDSS DR8恒星光谱中自动搜寻稀有天体
详细信息    查看全文 | 推荐本文 |
  • 英文篇名:Searching for Rare Celestial Objects Automatically from Stellar Spectra of the Sloan Digital Sky Survey Data Release Eight
  • 作者:司建敏 ; 罗阿理 ; 吴福朝 ; 吴毅红
  • 英文作者:SI Jian-min;LUO A-li;WU Fu-zhao;WU Yi-hong;National Laboratory of Pattern Recognition,Institute of Automation,Chinese Academy of Sciences;Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences;University of Chinese Academy of Sciences;
  • 关键词:核密度估计 ; K-近邻 ; 稀有天体 ; 数据挖掘 ; SDSS
  • 英文关键词:Kernel density estimation;;KNN;;Rare celestial objects;;Data mining,SDSS
  • 中文刊名:GUAN
  • 英文刊名:Spectroscopy and Spectral Analysis
  • 机构:中国科学院自动化研究所,模式识别国家重点实验室;中国科学院国家天文台,光学天文重点实验室;中国科学院大学;
  • 出版日期:2015-03-15
  • 出版单位:光谱学与光谱分析
  • 年:2015
  • 期:v.35
  • 基金:国家自然科学基金项目(10973021,61202315)资助
  • 语种:中文;
  • 页:GUAN201503060
  • 页数:7
  • CN:03
  • ISSN:11-2200/O4
  • 分类号:260-266
摘要
SDSS DR8海量光谱中包含许多有研究价值的稀有天体,如特殊白矮星(DZ,DQ,DC)、碳星、白矮主序双星、激变变星等,如何在海量光谱中自动搜寻稀有天体有着极其重要的意义。提出一种基于核密度估计和K-近邻(K-nearest neighbor,KNN)相结合的方法在SDSS DR8信噪比大于5的546 383个恒星光谱中搜寻稀有天体。首先对光谱进行高斯核密度估计,选取概率最小的5 000个光谱作为稀有类,概率最大的300 000个光谱作为普通类,然后进行KNN分类,同时也将5 000个稀有光谱的K个最近邻也作为稀有的天体,结果共有21 193条光谱。为了方便分析,对这些光谱聚类后进行人工检查。这些光谱主要包括由于数据缺失、红化、流量定标不准引起的问题光谱、行星状星云、没有物理联系的光谱双星、类星体、特殊白矮星(DZ,DQ,DC)、碳星、白矮主序双星、激变变星等。通过和SIMBAD,NED,ADS及一些主要的文献交叉验证,我们新发现了3个DZ白矮星、1个白矮主序双星、2个伴星为G型星的激变变星,3个激变变星的候选体、6个DC白矮星,1个DC白矮星候选体和1个BLLracertae(BLlac)候选体。还发现了1个有CaⅡ三重发射线和MgⅠ发射线的DA白矮星和1个光谱上表现出发射线的晚M恒星但测光图上像是一个星云或星系。
        There are many valuable rare and unusual objects in spectra dataset of Sloan Digital Sky Survey(SDSS) Data Release eight(DR8),such as special white dwarfs(DZ,DQ,DC),carbon stars,white dwarf main-sequence binaries(WDMS),cataclysmic variable(CV) stars and so on,so it is extremely significant to search for rare and unusual celestial objects from massive spectra dataset A novel algorithm based on Kernel dense estimation and K-nearest neighborhoods(KNN) has been presented,and applied to search for rare and unusual celestial objects from 546 383 stellar spectra of SDSS DR8.Their densities are estimated using Gaussian kernel density estimation,the top 5 000 spectra in descend order by their densities are selected as rare objects,and the top 300 000 spectra in ascend order by their densities are selected as normal objects.Then,KNN were used to classify the rest objects,and simultaneously K nearest neighbors of the 5 000 rare spectra are also selected as rare objects.As a result,there are totally 21 193 spectra selected as initial rare spectra,which include error spectra caused by deletion,redden,bad calibration,spectra consisting of different physically irrelevant components,planetary nebulas,QSOs,special white dwarfs(DZ,DQ,DC),carbon stars,white dwarf main-sequence binaries(WDMS),cataclysmic variable(CV) stars and so on.By cross identification with SIMBAD,NED,ADS and major literature,it is found that three DZ white dwarfs,one WDMS,two CVs with company of G-type star,three CVs candidates,six DC white dwarfs,one DC white dwarf candidate and one BL Lacertae(BL lac) candidate are our new findings.We also have found one special DA white dwarf with emission lines of Ca H triple and Mg I,and one unknown object whose spectrum looks like a late M star with emission lines and its image looks like a galaxy or nebula.
引文
[1]Dufour P,Bergeron P,Liebert J,et al.Astrophys J.,2007,663,1291.
    [2]Koester D,Girven J,Gansicke B T,et al.Astron.Astrophys.,2011,530:114.
    [3]Szkody P,Anderson S F,Agueros M,et al.Astron.J.,2002,123(1):430.
    [4]Szkody P,Fraser O,Silvestri N,et al.Astron.J.,2003,126(3):1499.
    [5]Szkody P,Henden A,Fraser O J,et al.Astron.J.,2004,128(4):18821893.
    [6]Szkody P,Henden A,Fraser O J,et al.Astron.J.,2005,129(5):2386.
    [7]Szkody P,Henden A,Agueros M,et al.Astron.J.,2006,131(2):973.
    [8]Szkody P,Henden A,Mannikko L,et al.Astron.J.,2007,134(1).185.
    [9]Szkody P,Anderson S F,Hayden M,et al.Astron.J.,2009,137(4):4011.
    [10]Szkody P,Anderson S F,Brooks K,et al.Astron.J.,2011,142(6):181.
    [11]Rebassa-Mansergas A,Agurto-GangasC,Schreiber M,et al.Mon.Not.R Astron.Soa,2013,433(4):3398.
    [12]Rebassa-Mansergas A,Nebot Gomez-MoranA,Schreiber M R,et al.Mon.Not.R Astron.Soa,2011,413:1121.
    [13]Tu L P,Luo A L,Wu F C,et al.Res.Astron.Astrophys.,2009,9(6):635.
    [14]Wei P,Luo A L,Li Y B,et al.Mon.Not.R Astron.Soa,,2013,431(2):1800.
    [15]Meusinger H,Schalldach P,Scholz R D,et al.Astron.Astrophys.,2012,541:77.
    [16]JIANG Bin,LUO A-li,ZHAO Yong-heng(姜斌,罗阿理,赵永恒).Spectrscopy and Spectral Analysis(光谱学和光谱分析).2012,32(2):510.
    [17]Margon B,Anderson S F,Harris H C,et al.Astron.J.,2002,124:1651.
    [18]Downes R A,Margon B,Anderson S F,et al.Astron.J.,2004,127:2838.
    [19]Paul Green.Astrophys.J.,2013,765:12.
    [20]Si J M,Luo A L,Li Y B,et al.Sri.China Phys.Mech.Astron.,2014,57(1):176.
    [21]Yang M S,Wu K L IEEE Trans.Pattern Anal.Mach.Intell.,2004,26(4):434.
    [22]Wu X D,Kumar V,Quinlan J S.Knowl.Inf.Syst,2008,14:1.
    [23]Kleinman S J,Keple SO,Koester D,et al.Astrophy.J.Supp.,2013,204(1):5.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700