A Bayesian estimation of the Milky Way's circular velocity curve using Gaia DR3

Abstract

Our goal is to calculate the circular velocity curve of the Milky Way, along with corresponding uncertainties that quantify various sources of systematic uncertainty in a self-consistent manner. The observed rotational velocities are described as circular velocities minus the asymmetric drift. The latter is described by the radial axisymmetric Jeans equation. We thus reconstruct the circular velocity curve between Galactocentric distances from 5 kpc to 14 kpc using a Bayesian inference approach. The estimated error bars quantify uncertainties in the Sun's Galactocentric distance and the spatial-kinematic morphology of the tracer stars. As tracers, we used a sample of roughly 0.6 million stars on the red giant branch stars with six-dimensional phase-space coordinates from Gaia data release 3 (DR3). More than 99% of the sample is confined to a quarter of the stellar disc with mean radial, rotational, and vertical velocity dispersions of $(35\pm 18)km/s$, $(25\pm 13)km/s$, and $(19\pm 9)km/s$, respectively. We find a circular velocity curve with a slope of $0.4\pm 0.6km/s/kpc$, which is consistent with a flat curve within the uncertainties. We further estimate a circular velocity at the Sun's position of $v_c(R_0)=233\pm 7km/s$ and that a region in the Sun's vicinity, characterised by a physical length scale of $\sim 1\mathrm{kpc}$, moves with a bulk motion of $V_{LSR}=7\pm 7km/s$. Finally, we estimate that the dark matter (DM) mass within 14 kpc is ${\log }_{10}{M}_{\mathrm{DM}}(R<14\mathrm{kpc})/{\mathrm{M}}_{\odot }=\left(11.2_{-2.3}^{+2.0}\right)$ and the local spherically averaged DM density is ${\rho }_{\mathrm{DM}}(R_0)=\left(0.41_{-0.09}^{+0.10}\right)GeV/c{\mathrm{m}}^3=\left(0.011_{-0.002}^{+0.003}\right){\mathrm{M}}_{\odot }/p{\mathrm{c}}^3$. In addition, the effect of biased distance estimates on our results is assessed.

References in corpus (26)

• Array Programming with NumPy
• The Gaia mission
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• The mass distribution in the Galactic Centre from interferometric astrometry of multiple stellar orbits
• Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry
• Improved GRAVITY astrometric accuracy from modeling of optical aberrations
• Evidence for dark matter in the inner Milky Way
• Gaia Data Release 3: Apsis II -- Stellar Parameters
• Gaia Data Release 3: Mapping the asymmetric disc of the Milky Way
• A classifier for spurious astrometric solutions in Gaia EDR3
• Dipping Our Toes in the Water: First Models of GD-1 as a Stream
• The power spectrum of the Milky Way: Velocity fluctuations in the Galactic disk
• The Circular Velocity Curve of the Milky Way from 5 to 25 kpc using luminous red giant branch star
• A direct measurement of the distance to the Galactic center using the kinematics of bar stars
• Mapping the Milky Way Disk with Gaia DR3: 3D extended kinematic maps and rotation curve to $\approx 30$ kpc
• Handling the Uncertainties in the Galactic Dark Matter Distribution for Particle Dark Matter Searches
• The Rotation Curve, Mass Distribution and Dark Matter Content of the Milky Way from Classical Cepheids
• Measuring the local dark matter density with LAMOST DR5 and Gaia DR2
• Kinematics and dynamics of Gaia red clump stars
• Line-of-sight velocity dispersions and a mass distribution model of the Sa galaxy NGC 4594
• Analysis of Determinations of the Distance between the Sun and the Galactic Center
• Measuring the Streaming motion in the Milky Way disc with Gaia EDR3 +
• Non-equilibrium in the Solar Neighbourhood using dynamical modelling with Gaia DR2
• Etudes on the Dynamics of Stellar Systems

Cited by in corpus (5)

• Study of Open Star Clusters Using the Gaia DR3: I- Poorly Studied King 2 and King 5
• SpectroTranslator: a deep-neural network algorithm to homogenize spectroscopic parameters
• Dark Matter Velocity Distributions for Direct Detection: Astrophysical Uncertainties are Smaller Than They Appear
• Three Models of the Gravitational Potential of the Milky Way
• Infrared photometry and CaT spectroscopy of the most metal-poor in-situ globular cluster VVV-CL001