Kinematics of the Galactic disk from LAMOST Dwarf sample

Abstract

Based on the LAMOST survey and Sloan Digital Sky Survey (SDSS), we use low-resolution spectra of 130,043 F/G-type dwarf stars to study the kinematics and metallicity properties of the Galactic disk. Our study shows that the stars with poorer metallicity and larger vertical distance from Galactic plane tend to have larger eccentricity and velocity dispersion. After separating the sample stars into likely thin-disk and thick-disk sub-sample, we find that there exits a negative gradient of rotation velocity $V_{\varphi }$ with metallicity [Fe/H] for the likely thin-disk sub-sample, and the thick-disk sub-sample exhibit a larger positive gradient of rotation velocity with metallicity. By comparing with model prediction, we consider the radial migration of stars appears to have influenced on the thin-disk formation. In addition, our results shows that the observed thick-disk stellar orbital eccentricity distribution peaks at low eccentricity ($e\sim 0.2$) and extends to a high eccentricity ($e\sim 0.8$). We compare this result with four thick-disk formation simulated models, and it imply that our result is consistent with gas-rich merger model.

arXiv comment9 pages, 11 figures, Accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1104.3114 by other authors

References in corpus (56)

• The Sloan Digital Sky Survey: Technical Summary
• SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems
• Local Kinematics and the Local Standard of Rest
• The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• SEGUE: A Spectroscopic Survey of 240,000 stars with g=14-20
• The New Galaxy: Signatures of its Formation
• Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the Solar neighbourhood
• Radial Mixing in Galactic Discs
• Elemental Abundance Survey of The Galactic Thick Disk
• Chemical evolution with radial mixing
• Kinematics of Metal-Poor Stars in the Galaxy. III. Formation of the Stellar Halo and Thick Disk as Revealed from a Large Sample of Non-Kinematically Selected Stars
• Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
• Simulations of Galaxy Formation in a Lambda CDM Universe II: The Fine Structure of Simulated Galactic Disks
• The Milky Way Tomography with SDSS: II. Stellar Metallicity
• LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The survey science plan
• Structure and Kinematics of the Stellar Halos and Thick Disks of the Milky Way Based on Calibration Stars from SDSS DR7
• Riding the Spiral Waves: Implications of Stellar Migration for the Properties of Galactic Disks
• The Galactic Thick Disk Stellar Abundances
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• The Emergence of the Thick Disk in a CDM Universe
• A New Mechanism for Radial Migration in Galactic Disks: Spiral-Bar Resonance Overlap
• Beyond Inside-Out Growth: Formation and Evolution of Disk Outskirts
• The ELODIE archive
• The Genesis of the Milky Way's Thick Disk via Stellar Migration
• The Gaia-ESO Survey: the Galactic Thick to Thin Disc transition
• A First Constraint on the Thick Disk Scale Length: Differential Radial Abundances in K Giants at Galactocentric Radii 4, 8, and 12 kpc
• Formation and Evolution of the Disk System of the Milky Way: [alpha/Fe] Ratios and Kinematics of the SEGUE G-Dwarf Sample
• Automatic Determination of Stellar Atmospheric Parameters and Construction of Stellar Spectral Templates of the Guoshoujing Telescope (LAMOST)
• The Milky Way Tomography with SDSS: III. Stellar Kinematics
• Kinematics of SDSS subdwarfs: Structure and substructure of the Milky Way halo
• The RAdial Velocity Experiment (RAVE): Third Data Release
• Tracing the Galactic thick disk to Solar metallicities
• A Short Scale Length for the α-Enhanced Thick Disk of the Milky Way: Evidence from Low-Latitude SEGUE Data
• The Emergence of the Thick Disk in a CDM Universe II: Colors and Abundance Patterns
• Estimation of the Tilt of the Stellar Velocity Ellipsoid from RAVE and Implications for Mass Models
• Effects of radial flows on the chemical evolution of the Milky Way disk
• Orbital Eccentricity as a probe of Thick Disk Formation Scenarios
• Two Disk Components from a Gas Rich Disk-Disk Merger
• Galactic kinematics and dynamics from RAVE stars
• The power spectrum of the Milky Way: Velocity fluctuations in the Galactic disk
• The Gaia-ESO Survey: Characterisation of the [alpha/Fe] sequences in the Milky Way discs
• APOGEE Kinematics I: Overview of the Kinematics of the Galactic Bulge as Mapped by APOGEE
• The 3D Velocity Structure of the Thick Disk from SPM4 and RAVE DR2
• Testing formation mechanisms of the Milky Way's thick disc with RAVE
• Evidence of a thick disk rotation-metallicity correlation
• The formation of a thick disk through the heating of a thin disk: Agreement with orbital eccentricities of stars in the solar neighborhood
• Kinematical and chemical vertical structure of the Galactic thick disk I. Thick disk kinematics
• Galactic structure studies with BATC star counts
• Observational Evidence from SDSS for a Merger Origin of the Milky Way's Thick Disk
• No evidence for a dark matter disk within 4 kpc from the Galactic plane
• Galactic structure studies from BATC survey
• Thick-disk evolution induced by the growth of an embedded thin disk
• Detailed Analysis of Nearby Bulge-like Dwarf Stars I. Stellar Parameters, Kinematics and Oxygen Abundances
• The thick disk rotation-metallicity correlation as a fossil of an "inverse chemical gradient" in the early Galaxy
• Estimation of Absolute Magnitude-dependent Galactic Model Parameters In Intermediate Latitude With SDSS and SCUSS

Cited by in corpus (11)

• Kinematics of the local disk from the RAVE survey and the Gaia first data release
• On the kinematics of a runaway Be star population
• Chemical and Kinematic Properties of the Galactic Disk from the LAMOST and Gaia Sample Stars
• Metallicity and Kinematics of the Galactic halo from the LAMOST sample stars
• Age-metallicity dependent stellar kinematics of the Milky Way disc from LAMOST and Gaia
• Insights into the Formation and Evolution History of the Galactic Disk System
• Vertical structure of Galactic disk kinematics from LAMOST K giants
• Element abundance analysis of the metal-rich stellar halo and high-velocitythick disk in the galaxy
• Vertical stellar density distribution in a non-isothermal galactic disc
• Existence of the Metal-Rich Stellar Halo and High-velocity Thick Disk in the Galaxy
• Not that simple: the metallicity dependence of the wide binary fraction changes with separation and stellar mass