A spectroscopic modelling method for the detached eclipsing binaries to derive atmospheric parameters

¹ CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Beijing 100101, PR China
e-mail: lal@nao.cas.cn; jjchen@nao.cas.cn
² School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, PR China
³ School of Information Management & Institute for Astronomical Science, Dezhou University, Dezhou 253023, PR China
⁴ School of Electronic Information Engineering, Hebei University of Technology, Tianjin 300401, PR China

Received: 7 March 2022
Accepted: 15 September 2022

Abstract

Based on luminosity contributions, we develop aspectroscopic modelling method to derive atmospheric parameters of component stars in binary systems. The method is designed for those spectra of binaries that show double-lined features due to radial-velocity differences between the component stars. We first derive the orbital parameters and the stellar radii by solving the light and radial-velocity curves. The luminosity contributions in different phases can then be calculated. We construct a synthesised double-lined spectra model by superposing theoretical single-star spectra according to the luminosity contributions. Finally, we derive the atmospheric parameters of each component star using the model-fitting method. For multi-epoch double-lined spectra observed by the Large sky Area Multi-Object Spectroscopic Telescope (LAMOST) Medium Resolution Survey (R ~ 7500), our method gives robust results for detached eclipsing binary systems observed in different orbital phases. Furthermore, this method can also be applied to other spectroscopic data with different resolutions as long as the systems are detached eclipsing binaries with nearly spherical stars.