Tracing the Origin of Moving Groups. III. Detecting Moving Groups in LAMOST DR7

Abstract

We revisit the moving groups (MGs) in the solar neighborhood with a sample of 91,969 nearby stars constructed from LAMOST DR7. Using the wavelet technique and Monte Carlo simulations, five MGs together with a new candidate located at V≃-130 km s^-1 are detected simultaneously in $V-\sqrt{{U}^{2}+2{V}^{2}}$ space. Taking into account the other known MGs, we conclude that MGs in the Galactic disk are spaced by approximately 15-25 km s^-1 along V velocity. The origin of detected MGs is analyzed through the distributions of [Fe/H]-[Mg/Fe] and ages. Our results support attributing the origin to the continuous resonant mechanisms probably induced by the bar or spiral arms of the Milky Way.