The substructures in the local stellar halo from Gaia and LAMOST

Abstract

Based on the second Gaia data release (Gaia DR2) and spectroscopy from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data, we identified 20,089 halo stars kinematically and chemically. The halo streams in the solar neighborhood could be detected in the space of energy and angular momentum. We reshuffle the velocities of these stars to determine the significance of substructure. Finally, we identify 4 statistically significant substructures that are labeled GL-1 through 4. Among these substructures, GL-1 is previously known stream ("N2" stream) and the rest 3 substructures are new. These substructures may be the debris of dwarf galaxies accretion event, their dynamical and chemical information can help to understand the history of the Milky Way.

12 pages, 9 figures, Accepted for publication in ApJ

References in corpus (16)

• scikit-image: Image processing in Python
• The mass distribution and gravitational potential of the Milky Way
• The Radial Velocity Experiment (RAVE): first data release
• Two Stellar Components in the Halo of the Milky Way
• An Orphan in the "Field of Streams"
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• Origin and evolution of moving groups I. Characterization in the observational kinematic-age-metallicity space
• The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric Spheroid
• A box full of chocolates: The rich structure of the nearby stellar halo revealed by Gaia and RAVE
• Satellites of Simulated Galaxies: survival, merging, and their relation to the dark and stellar halos
• Halo Star Streams in the Solar Neighborhood
• Fashionably Late? Building up the Milky Way's Inner Halo
• A Catalog of Moving Group Candidates in The Solar Neighborhood
• A comprehensive view of the Virgo Stellar Stream
• Stellar Stream Candidates in the Solar Neighborhood Found in the LAMOST DR3 and TGAS
• Three Moving Groups Detected in the LAMOST DR1 Archive

Cited by in corpus (3)

• Local RR Lyrae Stars: native and alien
• On the Origin of Metal-poor Stars in the Solar Neighborhood
• Existence of the Metal-Rich Stellar Halo and High-velocity Thick Disk in the Galaxy