正常星系光谱的一种谱线自动提取方法

正常星系的光谱是天体光谱谱线自动提取中最难处理的一种。文章针对正常星系光谱给出了一种新的谱线自动提取方法。首先，定义了两条光谱间的Max操作，Max操作的结果是生成了一条光谱，该光谱在每个波长处的强度取为在相应波长处强度较大的那一个光谱的强度;然后，通过迭代处理拟合连续谱，在每一步迭代中，先对原始光谱和前一步拟合出的连续谱进行Max操作，再对Max操作生成的光谱进行传统的连续谱拟合;最后，联合采用整体阈值处理和自适应的局部阈值处理提取谱线。实验结果表明：该方法的性能较之传统的小波方法有显著提高，这将对后续的基于谱线的光谱分类和参数测量非常有利。

An Auto-Extraction Method of Spectral Line for Normal Galaxy Spectra

Spectral line extraction for normal galaxy spectra is the most difficult task in spectral line auto-extraction of celestial spectra. The present paper presents a novel technique of spectral line auto-extraction for normal galaxy spectra. Firstly, the Max operator of two spectra is defined, and the operator produces a new spectrum whose intensity at each wavelength is the maximum of intensities of the two spectra; Secondly, the continuum is fitted in an iterative way, where in each iteration, the traditional wavelet method is performed for the spectrum obtained by the Max operation of the original spectrum, and the continuum is fitted in the last iteration; Finally, adaptive local thresholding associated with the universal thresholding is used to extract spectral lines. Experiments show that this method is superior to the traditional wavelet method. It will be helpful to the spectral line based automated spectral classification and parameter measurement.