Cresting the wave: Proper motions of the Eastern Banded Structure
arXiv:1709.08633 · doi:10.1093/mnras/stx2528
Abstract
We study the kinematic properties of the Eastern Banded Structure (EBS) and Hydra I overdensity using exquisite proper motions derived from the Sloan Digital Sky Survey (SDSS) and Gaia source catalog. Main sequence turn-off stars in the vicinity of the EBS are identified from SDSS photometry; we use the proper motions and, where applicable, spectroscopic measurements of these stars to probe the kinematics of this apparent stream. We find that the EBS and Hydra I share common kinematic and chemical properties with the nearby Monoceros Ring. In particular, the proper motions of the EBS, like Monoceros, are indicative of prograde rotation (V_phi ~ 180-220 km/s), which is similar to the Galactic thick disc. The kinematic structure of stars in the vicinity of the EBS suggest that it is not a distinct stellar stream, but rather marks the "edge" of the Monoceros Ring. The EBS and Hydra I are the latest substructures to be linked with Monoceros, leaving the Galactic anti-centre a mess of interlinked overdensities which likely share a unified, Galactic disc origin.
5 pages, 5 figures. MNRAS Letters accepted
References in corpus (9)
- Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
- The DESI Experiment Part I: Science,Targeting, and Survey Design
- The Milky Way Tomography with SDSS: II. Stellar Metallicity
- The SEGUE Stellar Parameter Pipeline. I. Description and Initial Validation Tests
- Rings and Radial Waves in the Disk of the Milky Way
- Substructure in Tidal Streams; Tributaries in the Anticenter Ring
- The Complex Structure of Stars in the Outer Galactic Disk as revealed by Pan-STARRS1
- The fall of the Northern Unicorn: Tangential motions in the Galactic Anti-centre with SDSS and Gaia
- The Metallicity of the Monoceros Stream