First Gaia dynamical model of the Milky Way disc with six phase space coordinates: a test for galaxy dynamics

Abstract

We construct the first comprehensive dynamical model for the high-quality subset of stellar kinematics of the Milky Way disc, with full 6D phase-space coordinates, provided by the Gaia Data Release 2. We adopt an axisymmetric approximation and use an updated Jeans Anisotropic Modelling (JAM) method, which allows for a generic shape and radial orientation of the velocity ellipsoid, as indicated by the Gaia data, to fit the mean velocities and all three components of the intrinsic velocity dispersion tensor. The Milky Way is the first galaxy for which all intrinsic phase space coordinates are available, and the kinematics are superior to the best integral-field kinematics of external galaxies. This situation removes the long-standing dynamical degeneracies and makes this the first dynamical model highly over-constrained by the kinematics. For these reasons, our ability to fit the data provides a fundamental test for both galaxy dynamics and the mass distribution in the Milky Way disc. We tightly constrain the volume average total density logarithmic slope, in the radial range 3.6--12 kpc, to be ${\alpha }_{\mathrm{tot}}=-2.149\pm 0.055$ and find that the dark halo slope must be significantly steeper than ${\alpha }_{\mathrm{DM}}=-1$ (NFW). The dark halo shape is close to spherical and its density is ${\rho }_{\mathrm{DM}}(R_{\odot })=0.0115\pm 0.0020$ M${}_{\odot }$ pc${}^{-3}$ ($0.437\pm 0.076$ GeV cm${}^{-3}$), in agreement with previous estimates. The circular velocity at the solar position $v_{\mathrm{circ}}(R_{\odot })=236.5\pm 3.1$ km s${}^{-1}$ (including systematics) and its gently declining radial trends are also consistent with recent determinations.

arXiv comment10 pages, 4 figures, 1 table. Accepted for publication in MNRAS

References in corpus (73)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Structure of Cold Dark Matter Halos
• The Gaia mission
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Local Kinematics and the Local Standard of Rest
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• Properties of galaxies reproduced by a hydrodynamic simulation
• The SAURON project - IV. The mass-to-light ratio, the virial mass estimator and the fundamental plane of elliptical and lenticular galaxies
• The mass distribution and gravitational potential of the Milky Way
• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• Halos and galaxies in the standard cosmological model: results from the Bolshoi simulation
• Response of dark matter halos to condensation of baryons: cosmological simulations and improved adiabatic contraction model
• The Radial Velocity Experiment (RAVE): first data release
• A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
• The Atlas3D project - XV. Benchmark for early-type galaxies scaling relations from 260 dynamical models: mass-to-light ratio, dark matter, Fundamental Plane and Mass Plane
• The Atlas3D project - XX. Mass-size and mass-sigma distributions of early-type galaxies: bulge fraction drives kinematics, mass-to-light ratio, molecular gas fraction and stellar initial mass function
• Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics
• Efficient Multi-Gaussian Expansion of galaxies
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• A direct dynamical measurement of the Milky Way's disk surface density profile, disk scale length, and dark matter profile at 4 kpc < R < 9 kpc
• Gaia Data Release 2: Mapping the Milky Way disc kinematics
• The Circular Velocity Curve of the Milky Way from $5$ to $25$ kpc
• Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution
• The Structure of the Milky Way's Bar Outside the Bulge
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• Galactoseismology: Discovery of Vertical Waves in the Galactic Disk
• The dynamical distance and intrinsic structure of the globular cluster omega Centauri
• Galaxy Masses
• Stars, Gas, and Dark Matter in the Solar Neighborhood
• Spiral arms, bar shape and bulge microlensing in the Milky Way
• Axisymmetric, 3-Integral Models of Galaxies: A Massive Black Hole in NGC3379
• Improved evidence for a black hole in M32 from HST/FOS spectra - II. Axisymmetric dynamical models
• The Milky Way's Stellar Disk
• Mass and shape of the Milky Way's dark matter halo with globular clusters from Gaia and Hubble
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• Constraining the Galaxy's dark halo with RAVE stars
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• Distribution functions for the Milky Way
• APOGEE: The Apache Point Observatory Galactic Evolution Experiment
• Evidence for an Intermediate-Mass Milky Way from Gaia DR2 Halo Globular Cluster Motions
• Distances and parallax bias in Gaia DR2
• Rotation curve of the Milky Way from Classical Cepheids
• Gravitational Lens Statistics for Generalized NFW Profiles: Parameter Degeneracy and Implications for Self-Interacting Cold Dark Matter
• Models of our Galaxy II
• Kinematic modelling of the Milky Way using the RAVE and GCS stellar surveys
• Dearth of dark matter or massive dark halo? Mass-shape-anisotropy degeneracies revealed by NMAGIC dynamical models of the elliptical galaxy NGC 3379
• Dynamical modelling of stars and gas in NGC2974: determination of mass-to-light ratio, inclination and orbital structure by Schwarzschild's method
• Small scatter and nearly-isothermal mass profiles to four half-light radii from two-dimensional stellar dynamics of early-type galaxies
• The Gravitational Force Field of the Galaxy Measured From the Kinematics of RR Lyrae in Gaia
• Displacement of the Sun from the Galactic Plane
• Efficient solution of the anisotropic spherically-aligned axisymmetric Jeans equations of stellar hydrodynamics for galactic dynamics
• More dynamical models of our Galaxy
• Recovering the intrinsic shape of early-type galaxies
• Dominant dark matter and a counter rotating disc: MUSE view of the low luminosity S0 galaxy NGC 5102
• Hubble Space Telescope proper motion (HSTPROMO) catalogs of Galactic globular clusters. III. Dynamical distances and mass-to-light ratios
• Kinematics of the local disk from the RAVE survey and the Gaia first data release
• A Milky Way with a massive, centrally concentrated thick disc: new Galactic mass models for orbit computations
• A centrally heated dark halo for our Galaxy
• The EDGE-CALIFA survey: validating stellar dynamical mass models with CO kinematics
• Assessing the Jeans Anisotropic Multi-Gaussian Expansion method with the Illustris simulation
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• The Tilt of the Local Velocity Ellipsoid as Seen by Gaia
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• The vertical force in the Solar Neighbourhood using red clump stars in TGASxRAVE - Constraints on the local dark matter density

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