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skysubtractionforlamost
Bai Zhongrui1; Zhang Haotong2; Yuan Hailong2; Li Guangwei2; Chen Jianjun2; Lei Yajuan2; Yang Huiqin2; Dong Yiqiao2; Wang Gang2; Zhao Yongheng1
刊名researchinastronomyandastrophysics
2017
卷号17期号:9页码:91
ISSN号1674-4527
英文摘要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) similar to 4 % fiber throughput uncertainty and small wavelength instability (0.1 angstrom) during observation. sky subtraction using principal component analysis (pca) further reduces 2 5 % of the sky line residual from oh lines 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 continuumintensity show that the sky emission line residual of lamost is smaller than that of the sdss survey.
语种英语
内容类型期刊论文
源URL[http://ir.bao.ac.cn/handle/114a11/48489]  
专题中国科学院国家天文台
作者单位1.中国科学院大学
2.中国科学院国家天文台
推荐引用方式
GB/T 7714
Bai Zhongrui,Zhang Haotong,Yuan Hailong,et al. skysubtractionforlamost[J]. researchinastronomyandastrophysics,2017,17(9):91.
APA Bai Zhongrui.,Zhang Haotong.,Yuan Hailong.,Li Guangwei.,Chen Jianjun.,...&Zhao Yongheng.(2017).skysubtractionforlamost.researchinastronomyandastrophysics,17(9),91.
MLA Bai Zhongrui,et al."skysubtractionforlamost".researchinastronomyandastrophysics 17.9(2017):91.
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