摘要
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)started a medianresolution spectroscopic(MRS,R~7500)survey since October 2018.The main scientific goals of MRS,including binary stars,pulsators and other variable stars,were launched with a time-domain spectroscopic survey.However,the systematic errors,including the bias induced from wavelength calibration and the systematic difference between different spectrographs,have to be carefully considered during radial velocity measurement.In this work,we provide a technique to correct the systematics in the wavelength calibration based on the relative radial velocity measurements from LAMOST MRS spectra.We show that,for the stars with multi-epoch spectra,the systematic bias which is induced from the exposures on different nights can be corrected well for LAMOST MRS in each spectrograph.In addition,the precision of radial velocity zero-point of multi-epoch time-domain observations reaches below 0.5 km s^(-1).As a by-product,we also give the constant star candidates^(**),which can be the secondary radial-velocity standard star candidates of LAMOST MRS time-domain surveys.
基金
supported by National Key R&D Program of China(No.2019YFA0405500)
the National Natural Science Foundation of China(NSFC,Grant No.11835057)
the State Natural Sciences Foundation Monumental Projects(Nos.12090040.Z.W.H,12090041.H.W.)
The Guoshoujing Telescope(the Large Sky Area Multi-Object Fiber Spectroscopic Telescope,LAMOST)is a National Major Scientific Project built by the Chinese Academy of Sciencesprovided by the National Development and Reform Commission。
