基于距离度量的LAMOST光谱中连续谱异常的自动检测

连续谱异常是指恒星光谱在获得和处理过程中由于星际消光和流量定标等原因造成连续谱严重偏离甚至中断的现象，这对光谱的谱线提取以及其他一些后续处理工作带来负面影响。提出了一种基于距离度量的连续谱异常光谱的自动检测方法，相比传统人眼检查在保证正确率的情况下大大地提高了工作效率。该方法首先通过光谱的lick线指数来确定待测光谱的恒星类型，同时对待测光谱进行归一化处理；然后分别提取待测光谱和对应类型模板光谱的连续谱；最后进行连续谱模板匹配，在每个波长点计算待测光谱和其模板光谱的流量差值，分析流量差值的分布，检验有多少差值点分布在在均值(β)附近的±α个标准差(δ)的范围内，进而可确定是否有连续谱异常。实验表明提出方法的可以快速有效的识别出连续谱异常的恒星光谱。

The Automatic Detection of the Continuum Problem in the Stellar Spectra Based on Distance Metric

Continuum problem is a phenomenon that the continuum of spectra get off their actual continuum even break off due to interstellar extinction and flux calibration ,and it will have negative impact on the subsequent process such as spectral line extrac-tion and so on .Due to this problem and considering of the continuum features of the stellar spectra ,a method of automatic detec-tion and recognition of the continuum problem in the stellar spectra is proposed ,which will improve work efficiency greatly com-pared with the traditional human eyes examination under the condition of maintaining high accuracy .Firstly in this method ,the subclass of the test stellar spectra is confirm by calculating the spectra 's lick indices ,and the test stellar spectra are normalized .Secondly ,the continuum of the test stellar spectra and the template spectra are fit with the same method .The last step goes to continuum template matching .The flux differences of the test stellar spectra and template spectra at every point of wavelength in the continuum spectra will be calculated to analyze the features of its distribution .The features counted are average (called β) value and standard deviation (calledδ) .The percentage of points distributed in range β± (a)*δwill be detected to confirm that if there is continuum problem .In the end ,this method has been proven to have a good effect on detecting and recognizing the con-tinuum problem spectra by a great deal of experiments .