Automatic Determination of Stellar Atmospheric Parameters and Construction of Stellar Spectral Templates of the Guoshoujing Telescope (LAMOST)

TL;DR

This paper develops and tests an automated method using ULySS to determine stellar atmospheric parameters from medium-resolution spectra, creating a spectral template library for the Guoshoujing Telescope to aid in large-scale stellar analysis.

Contribution

It introduces a reliable automated approach for measuring stellar parameters and constructs a spectral template library for the GSJT, enhancing data analysis capabilities.

Findings

ULySS reliably measures stellar parameters at R~2000

Achieved precisions of 167 K, 0.34 dex, 0.16 dex for Teff, log g, [Fe/H]

Constructed the first stellar spectral template library for GSJT

Abstract

A number of spectroscopic surveys have been carried out or are planned to study the origin of the Milky Way. Their exploitation requires reliable automated methods and softwares to measure the fundamental parameters of the stars. Adopting the ULySS package, we have tested the effect of different resolutions and signal-to-noise ratios (SNR) on the measurement of the stellar atmospheric parameters (effective temperature Teff, surface gravity log g, and metallicity [Fe/H]). We show that ULySS is reliable to determine these parameters with medium-resolution spectra (R~2000). Then, we applied the method to measure the parameters of 771 stars selected in the commissioning database of the Guoshoujing Telescope (GSJT). The results were compared with the SDSS/SEGUE Stellar Parameter Pipeline (SSPP), and we derived precisions of 167 K, 0.34 dex, and 0.16 dex for Teff, log g and [Fe/H] respectively. Furthermore, 120 of these stars are selected to construct the primary stellar spectra template library (Version 1.0) of GSJT, and will be deployed as basic ingredients for the GSJT automated parametrization pipeline.