Galaxy Spectrum Subtraction of a Mixed Spectrum Based on Two Class PCA Eigen-Spectra
TU Liang-ping1，2，WU Fu-chao1，LUO A-li3，ZHAO Yong-heng3
1. Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China 2. School of Science, Liaoning University of Science and Technology, Anshan 144051, China 3. National Observatories of China, Chinese Academy of Sciences, Beijing 100012, China
Abstract：The authors present a new method called two class PCA for decomposing the mixed spectra, namely, for subtracting the host galaxy contamination from each SN spectrum. The authors improved the quality of reconstructed galaxy spectrum and computational efficiency, and these improvements were realized because we used both the PCA eigen spectra of galaxy templates library and SN templates library to model the mixed spectrum. The method includes mainly three steps described as follows. The first step is calculating two class PCA eigen spectra of galaxy templates and SN templates respectively. The second step is determining all reconstructed coefficients by the SVD matrix decomposition or orthogonal transformation. And the third step is computing a reconstructed galaxy spectrum and subtracting it from each mixed spectrum. Experiments show that this method can obtain an accurate decomposition of a mixed synthetic spectrum, and is a method with low time-consumption to get the reliable SN spectrum without galaxy contamination and can be used for spectral analysis of large amount of spectra. The time consumption using our method is much lower than that using χ2-template fitting for a spectrum.
屠良平1，2，吴福朝1，罗阿理3，赵永恒3 . 基于二元PCA特征谱的星系光谱成分快速扣除 [J]. 光谱学与光谱分析, 2010, 30(06): 1707-1711.
TU Liang-ping1，2，WU Fu-chao1，LUO A-li3，ZHAO Yong-heng3 . Galaxy Spectrum Subtraction of a Mixed Spectrum Based on Two Class PCA Eigen-Spectra . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(06): 1707-1711.
[1] Frieman Joshua A. Bassett Bruce, Becker Andrew, et al. The Astronomical Journal, 2008, 135(1): 338. [2] LAMOST项目网.http://www.lamost.org/. [3] Blondin S, Walsh J R, Leibundgut B, et al. Astronomy and Astrophysics, 2005, 431: 757. [4] Darren S Madgwick, Paul C Hewett, Daniel J. Mortlock, et al. The Astrophysical Journal, 2003, 599: L33. [5] ZHANG Jian-nan, WU Fu-chao, LUO A-li, et al(张健楠，吴福朝，罗阿理，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25(12): 2088. [6] Richard O Duda, Peter E Hart, David G Stork. Pattern Classification, 2nd Edition. Wiley-Interscience, 2000. [7] Howell D A, Wang L. Bulletin of the American Astronomical Society(BAAS), 2002, 34: 1256. [8] Howell D A, Sullivan M, Perrett K, et al. The Astrophysical Journal, 2005, 634(2): 1190. [9] Lidman C, Howell D A, Folatelli G, et al. Astronomy and Astrophysics, 2005, 430: 843. [10] Hook I M, Howell D A, Aldering G, et al. The Astronomical Journal, 2005, 130(6): 2788. [11] Zheng Chen, Romani Roger W, Sako Masao, et al. The Astronomical Journal, 135(5): 1766. [12] Yip C W, Connolly A J, Szalay A S, et al. The Astronomical Journal, 2004, 128(2): 585. [13] Abazajian Kevork, Adelman-McCarthy Jennifer K, Agueros Marcel A, et al. The Astronomical Journal, 2003, 126(4): 2081. [14] Kinney A L, Calzetti D, Bohlin R C, et al. The Astrophysical Journal, 1996, 467: 38. [15] Abazajian K. The Astrophysical Journal Supplement, 2009, 182(2): 543. [16] Tu Liang-ping, Luo A-li, Wu Fu-chao, et al. Research in Astronomy and Astrophysics, 2009, 9(6): 635.
