The massive spectral data in LAMOST provides precious samples for scientific research in many fields in-cluding astronomy.It is an important research to identify weak features of stellar spectra for spectral data analysis,which can provide an important scientific basis for stellar spectral classification.At present,there are many methods for feature recognition based on stellar spectrum data,but few of them can accurately extract certain feature lines.Aiming at the diversified profile of Hα weak emission lines in LAMOST low-resolution spectral data,a method for identifying Hα weak emission lines based on confidence is proposed.First,based on the profile characteristics of the Hα weak emission line,a measure of the confidence of the Hα weak emission line is given.The distance confi-dence model is established by using the offset between the peak value and the emission line in the wavelength range of the Hα emission line,the Gaussian contour side information model is established according to the number of pix-els contained in the Gaussian contour,and the symmetry evaluation model is established by calculating the differ-ence between the waveforms on the left and right sides of the peak.The three models are combined to give the con-fidence of the final Hα weak emission line,and the first round of screening is performed based on this confidence.In order to improve the accuracy,it is proposed to use the characteristics of other emission lines to give a Hα emis-sion line screening strategy based on two classifications.By examining the characteristics of Hβ,NII,OIII and SII emission lines,the decision tree based on auxiliary information is used for the second round of screening to further improve the accuracy of screening.Experimental results show that the accuracy of the proposed Hα weak emission line feature measurement method is as high as 90%,and the speed is relatively fast,with an average of only more than 30 seconds per 1k data.
关键词
决策树/二元分类/置信度/弱发射线/LAMOST光谱数据
Key words
decision tree/binary classification/confidence/weak emission line/LAMOST spectral data
维普
万方数据