The Substructures in the Local Stellar Halo from Gaia and LAMOST
Abstract
Based on the second Gaia data release and spectroscopy from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope 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 four statistically significant substructures that are labeled GL-1 through 4. Among these substructures, GL-1 is a previously known stream (“N2” stream), and the other three substructures are new. These substructures may be the debris of dwarf galaxy accretion event; their dynamical and chemical information can help us to understand the history of the Milky Way.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2019
- DOI:
- 10.3847/1538-4357/ab06f4
- arXiv:
- arXiv:1902.04702
- Bibcode:
- 2019ApJ...874...74L
- Keywords:
-
- Galaxy: halo;
- Galaxy: kinematics and dynamics;
- solar neighborhood;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 12 pages, 9 figures, Accepted for publication in ApJ