New symbiotic stars or candidates in LAMOST low resolution spectra

Abstract: Symbiotic stars are among the most crucial binary systems for studying binary star interactions and Type Ia supernova progenitors. Based on the unique observational characteristics of symbiotic stars, strong H I, He I emission lines, giant spectral features, and the presence of [O III], He II, O VI, and other emission lines with ionization potentials exceeding 35 eV, and the Gaia information, we search for new symbiotic stars using the low-resolution spectroscopic survey data from LAMOST. Thirty-six binary systems have been selected as symbiotic stars or candidates, in which the five known symbiotic stars are included. Among them five systems (ZTF J005917.52+315605.4, ATO J094137.5+075304, LAMOST J200310.90+360822.6, LAMOST J072528.18+342530.4, and V* V758 Cyg) have been found as new symbiotic stars. Notably, LAMOST J072528.18+342530.4 and V* V758 Cyg were also confirmed as new symbiotic stars in a recent study. For the remaining 26 candidates, classification is based solely on the presence of [O III] emission lines (with ionization potentials > 35 eV) and the absence of He II high-excitation emission lines. Further observations are needed to confirm their nature as symbiotic stars.