Double-, triple-line spectroscopic candidates in the LAMOST Medium-Resolution Spectroscopic Survey

TL;DR

This paper utilizes the LAMOST-MRS survey data and a novel cross-correlation method to identify over 3,200 multi-line spectroscopic systems, mostly newly discovered, including binaries and triples, revealing their stellar evolutionary stages.

Contribution

It introduces a new approach using CCF and derivatives to detect multi-line spectroscopic systems in large survey data, significantly expanding known candidates.

Findings

Identified 3,133 binary and 132 triple candidates from 1.3 million spectra.

Over 95% of candidates are newly discovered.

All triple candidates are on the main sequence, with some binaries involving red giants.

Abstract

The LAMOST Medium-Resolution Spectroscopic Survey (LAMOST-MRS) provides an unprecedented opportunity for detecting multi-line spectroscopic systems. Based on the method of Cross-Correlation Function (CCF) and successive derivatives, we search for spectroscopic binaries and triples and derive their radial velocities (RVs) from the LAMOST-MRS spectra. A Monte-Carlo simulation is adopted to estimate the RV uncertainties. After examining over 1.3 million LAMOST DR7 MRS blue arm spectra, we obtain 3,133 spectroscopic binary (SB) and 132 spectroscopic triple (ST) candidates, which account for 1.2% of the LAMOST-MRS stars. Over 95% of the candidates are newly discovered. It is found that all of the ST candidates are on the main sequence, while around 10% of the SB candidates may have one or two components on the red giant branch.