Three Moving Groups Detected in the LAMOST DR1 Archive

We analyze the kinematics of thick disk and halo stars observed by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. We have constructed a sample of 7993 F, G, and K nearby main-sequence stars (d 3. Two of them (the Hyades-Pleiades stream and the Arcturus-AF06 stream) have been identified previously. We also find evidence for a new stream (centered at V ~ –180 km s–1) in the halo. The formation mechanisms of these three streams are analyzed. Our results support the hypothesis that the Arcturus-AF06 stream and the new stream originated from the debris of a disrupted satellite, while the Hyades-Pleiades stream has a dynamical origin.