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arXiv · 1405.0639

Three Moving Groups Detected in the LAMOST DR1 Archive

Jingkun Zhao·Gang Zhao·Yuqin Chen·Terry D. Oswalt·Kefeng Tan·Yong Zhang
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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 7,993 F, G and K nearby main-sequence stars (\textit{d} $<$ 2 kpc) with estimates of position (x, y, z) and space velocity ($U$, $V$, $W$) based on color and proper motion from the SDSS DR9 catalog. Three `phase-space overdensities' are identified in [\textit{V}, $\sqrt{U^{2}+2V^{2}}$] with significance levels of $\sigma$ $>$ 3. %[L$_{Z}$, eccentricity], [L$_{Z}$, L$_{\bot}$], and [V$_{az}$, V$_{\triangle}E$]. Two of them (Hyades-Pleiades stream, Arcturus-AF06 stream) have been identified previously. We also find evidence for a new stream (centered at \textit{V} $\sim$ -180 km s$^{-1}$) in the halo. The formation mechanisms of these three streams are analyzed. Our results support the hypothesis the Arcturus-AF06 stream and the new stream originated from the debris of a disrupted satellite, while Hyades-Pleiades stream has a dynamical origin.

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Jingkun Zhao, Gang Zhao, Yuqin Chen, Terry D. Oswalt, Kefeng Tan, Yong Zhang. 2014-05-04. Three Moving Groups Detected in the LAMOST DR1 Archive. https://doi.org/10.1088/0004-637x/787/1/31

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