Correction Factors of the Measurement Errors of the LAMOST-LRS Stellar Parameters  

作　　者：Shuhui Zhang Guozhen Hu Rongrong Liu Cuiyun Pan Lu Li Zhengyi Shao 

机构地区：[1]Key Laboratory for Research in Galaxies and Cosmology,Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Centre for Astrophysics and Planetary Science,Racah Institute of Physics,The Hebrew University,Jerusalem,91904,Israel [4]Key Lab for Astrophysics,Shanghai 200234,China

出　　处：《Research in Astronomy and Astrophysics》2023年第1期202-216,共15页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)under grants U2031139 and 12273091;the National Key R&D Program of China No.2019YFA0405501;the science research grants from the China Manned Space Project with No.CMS-CSST-2021-A08;the support of the UCAS Joint PHD Training Program;National Major Scientific Project built by the Chinese Academy of Sciences;provided by the National Development and Reform Commission。

摘　　要：We aim to investigate the propriety of stellar parameter errors of the official data release of the LAMOST lowresolution spectroscopy(LRS)survey.We diagnose the errors of radial velocity(RV),atmospheric parameters([Fe/H],Teff,logg)andα-enhancement([α/M])for the latest data release version of DR7,including 6,079,235effective spectra of 4,546,803 stars.Based on the duplicate observational sample and comparing the deviation of multiple measurements to their given errors,we find that,in general,the error of[α/M]is largely underestimated,and the error of RV is slightly overestimated.We define a correction factor k to quantify these misestimations and correct the errors to be expressed as proper internal uncertainties.Using this self-calibration technique,we find that the k-factors significantly vary with the stellar spectral types and the spectral signal-to-noise ratio(S/N).Particularly,we reveal a strange but evident trend between k-factors and error themselves for all five stellar parameters.Larger errors tend to have smaller k-factor values,i.e.,they were more overestimated.After the correction,we recreate and quantify the tight correlations between S/N and errors,for all five parameters,while these correlations have dependence on spectral types.It also suggests that the parameter errors from each spectrum should be corrected individually.Finally,we provide the error correction factors of each derived parameter of each spectrum for the entire LAMOST-LRS DR7 and plan to update them for the later data releases.

关 键 词：catalogs-methods data analysis-stars fundamental parameters 

分 类 号：P152[天文地球—天文学]