Weighing the local dark matter with RAVE red clump stars

Abstract

We determine the Galactic potential in the solar neigbourhood from RAVE observations. We select red clump stars for which accurate distances, radial velocities, and metallicities have been measured. Combined with data from the 2MASS and UCAC catalogues, we build a sample of 4600 red clump stars within a cylinder of 500 pc radius oriented in the direction of the South Galactic Pole, in the range of 200 pc to 2000 pc distances. We deduce the vertical force and the total mass density distribution up to 2 kpc away from the Galactic plane by fitting a distribution function depending explicitly on three isolating integrals of the motion in a separable potential locally representing the Galactic one with four free parameters. Because of the deep extension of our sample, we can determine nearly independently the dark matter mass density and the baryonic disc surface mass density. We find (i) at 1kpc Kz/(2piG) = 68.5 pm 1.0 Msun/pc2, and (ii) at 2 kpc Kz/(2piG) = 96.9 pm 2.2 Msun/pc2. Assuming the solar Galactic radius at R0 = 8.5 kpc, we deduce the local dark matter density rhoDM (z=0) = 0.0143 pm 0.0011Msun pc3 = 0.542 pm 0.042 Gev/cm3 and the baryonic surface mass density Sigma = 44.4 pm 4.1 Msun/pc2 . Our results are in agreement with previously published Kz determinations up to 1 kpc, while the extension to 2 kpc shows some evidence for an unexpectedly large amount of dark matter. A flattening of the dark halo of order 0.8 can produce such a high local density in combination with a circular velocity of 240 km/s . Another explanation, allowing for a lower circular velocity, could be the presence of a secondary dark component, a very thick disc resulting either from the deposit of dark matter from the accretion of multiple small dwarf galaxies, or from the presence of an effective phantom thick disc in the context of effective galactic-scale modifications of gravity.

14 pages, 13 figures, accepted to Astronomy and Astrophysics

References in corpus (14)

• The Radial Velocity Experiment (RAVE): first data release
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The RAVE Survey: Constraining the Local Galactic Escape Speed
• The Local Dark Matter Density
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• On the mass-to-light ratio of the local Galactic disc and the optical luminosity of the Galaxy
• The Radial Velocity Experiment (RAVE): second data release
• Vertical distribution of Galactic disk stars IV - AMR and AVR from clump giants
• A new determination of the local dark matter density from the kinematics of K dwarfs
• Radial and vertical flows induced by galactic spiral arms: likely contributors to our "wobbly Galaxy''
• Estimation of the Tilt of the Stellar Velocity Ellipsoid from RAVE and Implications for Mass Models
• The red clump absolute magnitude based on revised Hipparcos parallaxes
• Galactic kinematics with RAVE data: I. The distribution of stars towards the Galactic poles
• The Vertical Structure and Kinematics of Grand Design Spirals

Cited by in corpus (39)

• The mass distribution and gravitational potential of the Milky Way
• The Radial Velocity Experiment (RAVE): Fifth Data Release
• Dark matters on the scale of galaxies
• Predictions and Outcomes for the Dynamics of Rotating Galaxies
• MOA-II Galactic Microlensing Constraints: The Inner Milky Way has a Low Dark Matter Fraction and a Near Maximal Disk
• 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
• A centrally heated dark halo for our Galaxy
• Annual Modulation in Direct Dark Matter Searches
• Measuring the local dark matter density with LAMOST DR5 and Gaia DR2
• Modeling dark matter subhalos in a constrained galaxy: Global mass and boosted annihilation profiles
• The vertical effects of disc non-axisymmetries from perturbation theory: the case of the Galactic bar
• A measurement of the Galactic plane mass density from binary pulsar accelerations
• Bringing the Galaxy's dark halo to life
• The Third Law of Galactic Rotation
• Kinematics and dynamics of Gaia red clump stars
• Dark matter in galaxies
• Implications of a time-varying Galactic potential for determinations of the dynamical surface density
• The Stellar Distribution Function and Local Vertical Potential from Gaia DR2
• Action-based distribution function modelling for constraining the shape of the Galactic dark matter halo
• A self-consistent dynamical model of the Milky Way disc adjusted to Gaia data
• Mapping Dark Matter in the Milky Way using Normalizing Flows and Gaia DR3
• Weighing the Galactic disk in sub-regions of the solar neighbourhood using Gaia DR2
• The oblateness of the Milky Way dark matter halo from the stellar streams of NGC 3201, M68, and Palomar 5
• Making sense of the local Galactic escape speed estimates in direct dark matter searches
• Testing MOdified Gravity (MOG) theory and dark matter model in Milky Way using the local observables
• Informing dark matter direct detection limits with the ARTEMIS simulations
• Galactic structure in the outer disk: the field in the line of sight to the intermediate-age open cluster Tombaugh 1
• The North/South Asymmetry of the Galaxy: Possible Connection to the Vertical Phase Space Snail
• The Dynamical Response of Dark Matter to Galaxy Evolution Affects Direct-Detection Experiments
• Young and Intermediate-age Distance Indicators
• Measuring the local Dark Matter density in the laboratory
• Quantifying torque from the Milky Way bar using Gaia DR2
• Vertical stellar density distribution in a non-isothermal galactic disc
• A method to calculate the local density distribution of the Galaxy from the Tycho-Gaia Astrometric Solution data
• Local dark matter density from Gaia DR3 K-dwarfs using Gaussian processes
• MOND and Methodology
• Exploring Milky Way rotation curves with Gaia DR3: a comparison between $\Lambda$CDM, MOND, and General Relativistic approaches
• Comparing dark matter and MOND hyphotheses from the distribution function of A, F, early-G stars in the solar neighbourhood