在SDSS DR8恒星光譜中自動(dòng)搜尋稀有天體
發(fā)布時(shí)間：2019-03-16 13:30
【摘要】：SDSS DR8海量光譜中包含許多有研究價(jià)值的稀有天體,如特殊白矮星(DZ,DQ,DC)、碳星、白矮主序雙星、激變變星等,如何在海量光譜中自動(dòng)搜尋稀有天體有著極其重要的意義。提出一種基于核密度估計(jì)和K-近鄰(K-nearest neighbor,KNN)相結(jié)合的方法在SDSS DR8信噪比大于5的546 383個(gè)恒星光譜中搜尋稀有天體。首先對(duì)光譜進(jìn)行高斯核密度估計(jì),選取概率最小的5 000個(gè)光譜作為稀有類,概率最大的300 000個(gè)光譜作為普通類,然后進(jìn)行KNN分類,同時(shí)也將5 000個(gè)稀有光譜的K個(gè)最近鄰也作為稀有的天體,結(jié)果共有21 193條光譜。為了方便分析,對(duì)這些光譜聚類后進(jìn)行人工檢查。這些光譜主要包括由于數(shù)據(jù)缺失、紅化、流量定標(biāo)不準(zhǔn)引起的問題光譜、行星狀星云、沒有物理聯(lián)系的光譜雙星、類星體、特殊白矮星(DZ,DQ,DC)、碳星、白矮主序雙星、激變變星等。通過和SIMBAD,NED,ADS及一些主要的文獻(xiàn)交叉驗(yàn)證,我們新發(fā)現(xiàn)了3個(gè)DZ白矮星、1個(gè)白矮主序雙星、2個(gè)伴星為G型星的激變變星,3個(gè)激變變星的候選體、6個(gè)DC白矮星,1個(gè)DC白矮星候選體和1個(gè)BLLracertae(BLlac)候選體。還發(fā)現(xiàn)了1個(gè)有CaⅡ三重發(fā)射線和MgⅠ發(fā)射線的DA白矮星和1個(gè)光譜上表現(xiàn)出發(fā)射線的晚M恒星但測(cè)光圖上像是一個(gè)星云或星系。
[Abstract]:The massive spectrum of SDSS DR8 contains many rare objects of research value, such as special white dwarf star (DZ,DQ,DC), carbon star, white dwarf main sequence binary star, cataclysmic star, etc. How to automatically search for rare objects in massive spectra is of great significance. A method based on the combination of kernel density estimation and K-nearest neighbor (K-nearest neighbor,KNN) is proposed to search for rare objects in the spectra of 546,383 stars with SDSS DR8 signal-to-noise ratio greater than 5. In this paper, we first estimate the density of the spectrum by Gao Si's kernel, select the 5,000 spectra with the lowest probability as the rare class, and the 300,000 spectra with the highest probability as the general class, and then carry on the KNN classification. At the same time, K nearest neighbors of 5 000 rare spectra are also regarded as rare objects. The results show that there are 21 193 spectra. In order to facilitate the analysis, after clustering these spectra, the manual examination was carried out. These spectra mainly include problems caused by lack of data, redness, flow calibration, planetary nebulae, spectral binaries that have no physical connection, quasars, special white dwarfs (DZ,DQ,DC), carbon stars, and white dwarf main sequence binary stars. To change the magnitude of a star. Through cross-validation with SIMBAD,NED,ADS and some major literatures, we have discovered three new DZ white dwarf stars, one white dwarf binary star, two mutable stars of type G, three candidates of cataclysmic stars, and six DC white dwarf stars. One DC white dwarf candidate and one BLLracertae (BLlac) candidate. A DA white dwarf star with Ca 鈪，
本文編號(hào)：2441464
[Abstract]:The massive spectrum of SDSS DR8 contains many rare objects of research value, such as special white dwarf star (DZ,DQ,DC), carbon star, white dwarf main sequence binary star, cataclysmic star, etc. How to automatically search for rare objects in massive spectra is of great significance. A method based on the combination of kernel density estimation and K-nearest neighbor (K-nearest neighbor,KNN) is proposed to search for rare objects in the spectra of 546,383 stars with SDSS DR8 signal-to-noise ratio greater than 5. In this paper, we first estimate the density of the spectrum by Gao Si's kernel, select the 5,000 spectra with the lowest probability as the rare class, and the 300,000 spectra with the highest probability as the general class, and then carry on the KNN classification. At the same time, K nearest neighbors of 5 000 rare spectra are also regarded as rare objects. The results show that there are 21 193 spectra. In order to facilitate the analysis, after clustering these spectra, the manual examination was carried out. These spectra mainly include problems caused by lack of data, redness, flow calibration, planetary nebulae, spectral binaries that have no physical connection, quasars, special white dwarfs (DZ,DQ,DC), carbon stars, and white dwarf main sequence binary stars. To change the magnitude of a star. Through cross-validation with SIMBAD,NED,ADS and some major literatures, we have discovered three new DZ white dwarf stars, one white dwarf binary star, two mutable stars of type G, three candidates of cataclysmic stars, and six DC white dwarf stars. One DC white dwarf candidate and one BLLracertae (BLlac) candidate. A DA white dwarf star with Ca 鈪，
本文編號(hào)：2441464
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