Exploring the Galactic Anticenter substructure with LAMOST & Gaia DR2

Abstract

We characterize the kinematic and chemical properties of 589 Galactic Anticenter Substructure Stars (GASS) with K-/M- giants in Integrals-of-Motion space. These stars likely include members of previously identified substructures such as Monoceros, A13, and the Triangulum-Andromeda cloud (TriAnd). We show that these stars are on nearly circular orbits on both sides of the Galactic plane. We can see velocity($V_Z$) gradient along Y-axis especially for the south GASS members. Our GASS members have similar energy and angular momentum distributions to thin disk stars. Their location in [$\alpha$/M] vs. [M/H] space is more metal poor than typical thin disk stars, with [$\alpha$/M] \textbf{lower} than the thick disk. We infer that our GASS members are part of the outer metal-poor disk stars, and the outer-disk extends to 30 kpc. Considering the distance range and $\alpha$-abundance features, GASS could be formed after the thick disk was formed due to the molecular cloud density decreased in the outer disk where the SFR might be less efficient than the inner disk.

17 pages, 8 figures

References in corpus (69)

• The Sloan Digital Sky Survey: Technical Summary
• Gaia Data Release 2. Summary of the contents and survey properties
• Local Kinematics and the Local Standard of Rest
• The observed properties of dwarf galaxies in and around the Local Group
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the Solar neighbourhood
• The Radial Velocity Experiment (RAVE): first data release
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• Two Stellar Components in the Halo of the Milky Way
• The Faintest Dwarf Galaxies
• LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The survey science plan
• A dynamically young and perturbed Milky Way disk
• Structure and Kinematics of the Stellar Halos and Thick Disks of the Milky Way Based on Calibration Stars from SDSS DR7
• A Low Latitude Halo Stream around the Milky Way
• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• Footprints of the Sagittarius dwarf galaxy in the $Gaia$ data set
• Old stellar Galactic disc in near-plane regions according to 2MASS: scales, cut-off, flare and warp
• One Ring to Encompass them All: A giant stellar structure that surrounds the Galaxy
• Rings and Radial Waves in the Disk of the Milky Way
• The GALAH survey and Gaia DR2: dissecting the stellar disc's phase space by age, action, chemistry and location
• Kinematics of Metal-Poor Stars in the Galaxy. II. Proper Motions for a Large Non-Kinematically Selected Sample
• The Case for the Dual Halo of the Milky Way
• Deciphering The Last Major Invasion of the Milky Way Galaxy
• When the Milky Way turned off the lights: APOGEE provides evidence of star formation quenching in our Galaxy
• Response of the Milky Way's disc to the Large Magellanic Cloud in a first infall scenario
• Carbon-Enhanced Metal-Poor Stars in the Inner and Outer Halo Components of the Milky Way
• The origin of the Gaia phase-plane spiral
• A Short Scale Length for the α-Enhanced Thick Disk of the Milky Way: Evidence from Low-Latitude SEGUE Data
• Substructure in bulk velocities of Milky Way disk stars
• The Stellar Metallicity Distribution Function of the Galactic Halo from SDSS Photometry
• The SEGUE K giant survey II: A Catalog of Distance Determinations for the SEGUE K giants in the Galactic Halo
• Spiral structure of the Third Galactic Quadrant and the solution to the Canis Major debate
• Early evolution of the Galactic halo revealed from Hipparcos observations of metal-poor stars
• A fully cosmological model of a Monoceros-like ring
• The K giant stars from the LAMOST survey data I: identification, metallicity, and distance
• Population Studies. XIII. A New Analysis of the Bidelman-MacConnell "Weak-Metal" Stars - Confirmation of Metal-Poor Stars in the Thick Disk of the Galaxy
• Fashionably Late? Building up the Milky Way's Inner Halo
• Carbon-Enhanced Metal-Poor Stars: CEMP-s and CEMP-no Sub-Classes in the Halo System of the Milky Way
• Mapping the Milky Way with LAMOST III: Complicated spatial structure in the outer disc
• Cepheid Variables in the Flared Outer Disk of our Galaxy
• The Complex Structure of Stars in the Outer Galactic Disk as revealed by Pan-STARRS1
• Carbon stars identified from LAMOST DR4 using Machine Learning
• Anisotropy of the Milky Way's stellar halo using K giants from LAMOST and $Gaia$
• Simulations of minor mergers. II. The phase-space structure of thick discs
• Clustering of Local Group distances: publication bias or correlated measurements? IV. The Galactic Center
• Group finding in the stellar halo using M-giants in 2MASS: An extended view of the Pisces Overdensity?
• TriAnd and its Siblings: Satellites of Satellites in the Milky Way Halo
• A New Analysis of RR Lyrae Kinematics in the Solar Neighborhood
• On Rings and Streams in the Galactic Anti-Center
• A Disk Origin for the Monoceros Ring and A13 Stellar Overdensities
• Mapping the Galactic disk with the LAMOST and Gaia Red clump sample. II. 3D asymmetrical kinematics of mono-age populations in the disk between 6$-14$ \,kpc
• Time stamps of vertical phase mixing in the Galactic disk from LAMOST-Gaia stars
• Tracing Kinematic and Chemical Properties of Sagittarius Stream by K-Giants, M-Giants, and BHB stars
• Exploring the pertubed Milky Way disk and the substructures of the outer disk
• The Chemical Evolution of the Monoceros Ring/Galactic Anticenter Stellar Structure
• Carbon stars from LAMOST DR2 data
• Selecting M-giants with infra-red photometry: Distances, metallicities and the Sagittarius stream
• Exploring Halo Substructure with Giant Stars. XV. Discovery of a Connection between the Monoceros Ring and the Triangulum-Andromeda Overdensity?
• Value-added catalogs of M type stars in LAMOST DR5
• Modeling Star counts in the Monoceros stream and the Galactic anti-centre
• Identifying Galactic Halo Substructure in 6D Phase-space Using $\sim$13,000 LAMOST K Giants
• Searching for spiral features in the outer Galactic disk. The field towards WR38 and WR38a
• Clustering of Local Group distances: publication bias or correlated measurements? V. Galactic rotation constants
• Disk-Like Chemistry of the Triangulum-Andromeda Overdensity as Seen by APOGEE
• The Metallicity of the Monoceros Stream
• Ripple patterns in in-plane velocities of OB stars from LAMOST and Gaia
• Kinematics of Nearby Subdwarf Stars
• The local spiral arm in the LAMOST-Gaia common stars?

Cited by in corpus (8)

• The Pristine survey -- XXIII. Data Release 1 and an all-sky metallicity catalogue based on Gaia DR3 BP/RP spectro-photometry
• Constructing the Milky Way Stellar Halo in the Galactic Center by Direct Orbit Integration
• Value-added catalog of M-giant stars in LAMOST DR9
• Measuring the Streaming motion in the Milky Way disc with Gaia EDR3 +
• The Chemodynamical Nature of the Triangulum-Andromeda Overdensity
• The Correlation Between Dust and Gas Contents in Molecular Clouds
• Unveiling Galactic substructures with M Giant stars: A kinematic and chemical study based on LAMOST DR9, Gaia DR3 and APOGEE DR17
• Multiple Populations in Low-mass Globular Clusters: Eridanus