LAMOST低分辨率光谱中A型星的恒星参数测量新方法OA北大核心CSTPCD

The stellar spectroscopic surveys represented by LAMOST have generated a vast amount of A-type star spectra.Accurately measuring the atmospheric physical parameters from low-resolution spectra of A-type stars and forming a unified processing pipeline is often affected by special A-type stars.This paper discusses the spectral features of special A-type stars,Am and Ae in the optical band.Am stars are characterized by weak Ca II lines and strong Fe lines,while Ae stars are distinguished by emission lines in their spectra.By shielding the spectral regions in Am and Ae stars that have a significant impact on the measurement of atmospheric parameters and retaining regions sensitive to stellar parameters as much as possible,we have obtained a unified algorithm for measuring the atmospheric parameters of A-type stars.This method will be applied to LAMOST Data Release 11(DR11)and subsequent data products.Through statistical analysis of parameters from repeated observations,the precisions for effective temperature(Teff),surface gravity(lg g)and metallicity([Fe/H])are found to be 108 K,0.103 dex,and 0.074 dex,respectively.External comparison analysis with the high-resolution catalog PASTEL reveals that the standard deviations for Teff,lg g,and[Fe/H]obtained by this method are 234 K,0.283 dex,and 0.327 dex,respectively.