The Backgroud Sky Subtraction Around [OIII] Line in LAMOST QSO Spectra
SHI Zhi-xin1, 2, 3, Georges Comte2, 4, LUO A-li2*, TU Liang-ping5, ZHAO Yong-heng2, WU Fu-chao1
1. National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China 2. Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 3. University of Chinese Academy of Sciences, Beijing 100049, China 4. Aix-Marseille Université, CNRS, Institut Pythéas, L.A.M., UMR 7326, F-13388 Marseille Cedex, France 5. School of Science, University of Science and Technology, Anshan 144051, China
Abstract：At present, most sky-subtraction methods focus on the full spectrum, not the particular location, especially for the backgroud sky around [OIII] line which is very important to low redshift quasars. A new method to precisely subtract sky lines in local region is proposed in the present paper, which sloves the problem that the width of Hβ-[OIII] line is effected by the backgroud sky subtraction. The exprimental results show that, for different redshift quasars, the spectral quality has been significantly improved using our method relative to the original batch program by LAMOST. It provides a complementary solution for the small part of LAMOST spectra which are not well handled by LAMOST 2D pipeline. Meanwhile, This method has been used in searching for candidates of double-peaked Active Galactic Nuclei.
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