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 < 2 kpc) with estimates of position (x, y, z) and space velocity (U, V, W) based on color and proper motion from the Sloan Digital Sky Survey DR9 catalog. Three “phase-space overdensities” are identified in (V,√U2 + 2V 2) with significance levels of σ > 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.
The Astrophysical Journal
Scholarly Commons Citation
K., Z. J., G., Z., Chen, Y. Q., Oswalt, T. D., Tan, K. F., & Zhang, Y. (2014). Three Moving Groups Detected in the LAMOST DR1 Archive. The Astrophysical Journal, 787(1). https://doi.org/10.1088/0004-637X/787/1/31