Spectral classification and composites of galaxies in LAMOST DR4
Spectral classification and composites of galaxies in LAMOST DR4
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DOI：
10.1093/mnras/stx2798
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发表时间：
2017-10
影响因子：
4.8
通讯作者：
Li-Li Wang-Li;A. Luo;S. Shen;W. Hou;X. Kong;Yi-Han Song;Jian-Na Zhang;Wu Hong;Z. Cao;Yong-Hui Hou;Yuefei Wang;Yong Zhang;Yongheng Zhao
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文献类型：
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作者：
Li-Li Wang-Li;A. Luo;S. Shen;W. Hou;X. Kong;Yi-Han Song;Jian-Na Zhang;Wu Hong;Z. Cao;Yong-Hui Hou;Yuefei Wang;Yong Zhang;Yongheng Zhao
本文研究了大天区面积多目标光纤光谱望远镜（LAMOST）第四次数据发布（DR 4）中星系的分类和合成光谱。我们选取了40，182个LAMOST DR 4星系的光谱，这些星系在斯隆数字巡天（SDSS）中没有光谱观测，但有光度信息。用谱线强度（H\B{eta}，[OIII]{\lambda}5007，H {\alpha}和[NII]{\lambda}6585）对这些新观测到的光谱进行了重新标定，并将其分为六类，即被动谱、H{\alpha}-弱谱、成星谱、合成谱、LINER谱和Seyfert谱。通过浓度指数、（u-r）颜色和D4000 n指数三个参数研究了光谱类与形态类型之间的相关性。计算了6个谱类的高信噪比合成谱，从中提取出一些能有效区分谱类的特征，包括H B{eta}、Fe 5015、H{\gamma}A、HK和Mg 2等谱带，并与SDSS谱进行了比较，分析了它们的差异。一个包含40，182个新观测光谱（36，601个目标）的星系目录和六个类别的合成光谱可在网上查阅。
We study the classification and composite spectra of galaxy in the fourth data release (DR4) of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). We select 40,182 spectra of galaxies from LAMOST DR4, which have photometric in- formation but no spectroscopic observations in the Sloan Digital Sky Survey(SDSS). These newly observed spectra are re-calibrated and classified into six classes, i.e. pas- sive, H{\alpha}-weak, star-forming, composite, LINER and Seyfert using the line intensity (H\b{eta}, [OIII]{\lambda}5007, H{\alpha} and [NII]{\lambda}6585). We also study the correlation between spectral classes and morphological types through three parameters: concentration index, (u - r) color, and D4000n index. We calculate composite spectra of high signal-to-noise ra- tio(S/N) for six spectral classes, and using these composites we pick out some features that can differentiate the classes effectively, including H\b{eta}, Fe5015, H{\gamma}A, HK, and Mg2 band etc. In addition, we compare our composite spectra with the SDSS ones and analyse their difference. A galaxy catalogue of 40,182 newly observed spectra (36,601 targets) and the composite spectra of the six classes are available online.