Three Moving Groups Detected in the LAMOST DR1 Archive
Abstract
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, \sqrt{U^{2}+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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2014
- DOI:
- 10.1088/0004-637X/787/1/31
- arXiv:
- arXiv:1405.0639
- Bibcode:
- 2014ApJ...787...31Z
- Keywords:
-
- Galaxy: kinematics and dynamics;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 7 pages, 5 figures