Gaia-DR2 extended kinematical maps. Part III: Rotation curves analysis, dark matter, and Modified Newtonian dynamics tests

Abstract

Recent statistical deconvolution methods have produced extended kinematical maps in a range of heliocentric distances that are a factor of two to three larger than those analysed in the Gaia Collaboration based on the same data. In this paper, we use such maps to derive the rotation curve both in the Galactic plane and in off-plane regions and to analyse the density distribution. By assuming stationary equilibrium and axisymmetry, we used the Jeans equation to derive the rotation curve. Then we fit it with density models that include both dark matter and predictions of the MOND (Modified Newtonian dynamics) theory. Since the Milky Way exhibits deviations from axisymmetry and equilibrium, we also considered corrections to the Jeans equation. To compute such corrections, we ran N-body experiments of mock disk galaxies where the departure from equilibrium becomes larger as a function of the distance from the centre. The rotation curve in the outer disk of the Milky Way that is constructed with the Jeans equation exhibits very low dependence on $R$ and $z$ and it is well-fitted both by dark matter halo and MOND models. The application of the Jeans equation for deriving the rotation curve, in the case of the systems that deviate from equilibrium and axisymmetry, introduces systematic errors that grow as a function of the amplitude of the average radial velocity. In the case of the Milky Way, we can observe that the amplitude of the radial velocity reaches $\sim 10\%$ that of the azimuthal one at $R\approx 20$ kpc. Based on this condition, using the rotation curve obtained from the Jeans equation to calculate the mass may overestimate its measurement.

arXiv comment11 pages, 8 figures, accepted to be published in A&A

References in corpus (40)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Structure of Cold Dark Matter Halos
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• Gaia Data Release 2: The astrometric solution
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• Gaia Data Release 2: using Gaia parallaxes
• Gaia Data Release 2: Catalogue validation
• A dynamically young and perturbed Milky Way disk
• Gaia Data Release 2: Mapping the Milky Way disc kinematics
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• The Circular Velocity Curve of the Milky Way from $5$ to $25$ kpc
• Evidence for a systematic offset of -80 micro-arcseconds in the Gaia DR2 parallaxes
• Unified Rotation Curve of the Galaxy -- Decomposition into de Vaucouleurs Bulge, Disk, Dark Halo, and the 9-kpc Rotation Dip --
• Gaia Radial Velocity Spectrometer
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• Gaia Data Release 2: Properties and validation of the radial velocities
• The Milky Way's rotation curve out to 100 kpc and its constraint on the Galactic mass distribution
• Fundamental Parameters of the Milky Way Galaxy Based on VLBI astrometry
• Confirmation of the $Gaia$ DR2 parallax zero-point offset using asteroseismology and spectroscopy in the $Kepler$ field
• Gaia Data Release 2: The catalogue of radial velocity standard stars
• Rotation curve of the Milky Way from Classical Cepheids
• Estimating distances from parallaxes. II. Performance of Bayesian distance estimators on a Gaia-like catalogue
• Rotation Curve of the Milky Way out to $\sim$ 200 kpc
• Gaia Data Release 2: Processing the spectroscopic data
• The origin of the Gaia phase-plane spiral
• Stellar density profile and mass of the Milky Way Bulge from VVV data
• 3D Asymmetrical motions of the Galactic outer disk with LAMOST K giant stars
• The Mass Distribution and Rotation Curve in the Galaxy
• 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
• Implications of a time-varying Galactic potential for determinations of the dynamical surface density
• Gaia-DR2 extended kinematical maps. Part I: Method and application
• Milky Way rotation curve from proper motions of red clump giants
• Testing Dark Matter and Modifications to Gravity using Local Milky Way Observables
• Long-lived transient structure in collisionless self-gravitating systems
• Transient spiral arms from far out of equilibrium gravitational evolution
• Transverse gradients of azimuthal velocity in a global disk model of the Milky Way

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• Mass models of the Milky Way and estimation of its mass from the GAIA DR3 data-set
• Constraining the Gravitational Potential from the Projected Morphology of Extragalactic Tidal Streams
• A Bayesian estimation of the Milky Way's circular velocity curve using Gaia DR3
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• On the Galactic rotation curve inferred from the Jeans equations Assessing its robustness using Gaia DR3 and cosmological simulations
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