Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution

Abstract

We construct a large set of dynamical models of the galactic bulge, bar and inner disk using the Made-to-Measure method. Our models are constrained to match the red clump giant density from a combination of the VVV, UKIDSS and 2MASS infrared surveys together with stellar kinematics in the bulge from the BRAVA and OGLE surveys, and in the entire bar region from the ARGOS survey. We are able to recover the bar pattern speed and the stellar and dark matter mass distributions in the bar region, thus recovering the entire galactic effective potential. We find a bar pattern speed of $39.0\pm 3.5\mathrm{km}{\mathrm{s}}^{-1}\mathrm{kp}{\mathrm{c}}^{-1}$, placing the bar corotation radius at $6.1\pm 0.5\mathrm{kpc}$ and making the Milky Way bar a typical fast rotator. We evaluate the stellar mass of the long bar and bulge structure to be $M_{bar/bulge}=1.88\pm 0.12\times 10^{10}{\mathrm{M}}_{\odot }$, larger than the mass of disk in the bar region, $M_{\mathrm{inner}\mathrm{disk}}=1.29\pm 0.12\times 10^{10}{\mathrm{M}}_{\odot }$. The total dynamical mass in the bulge volume is $1.85\pm 0.05\times 10^{10}{\mathrm{M}}_{\odot }$. Thanks to more extended kinematic data sets and recent measurement of the bulge IMF our models have a low dark matter fraction in the bulge of $17\%\pm 2\%$. We find a dark matter density profile which flattens to a shallow cusp or core in the bulge region. Finally, we find dynamical evidence for an extra central mass of $\sim 0.2\times 10^{10}{\mathrm{M}}_{\odot }$, probably in a nuclear disk or disky pseudobulge.

in press

References in corpus (28)

• Improving PARSEC models for very low mass stars
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• The Local Dark Matter Density
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• Baryon effects on the internal structure of LCDM halos in the EAGLE simulations
• The Structure of the Milky Way's Bar Outside the Bulge
• Constraining the Galaxy's dark halo with RAVE stars
• Made-to-Measure models of the Galactic Box/Peanut bulge: stellar and total mass in the bulge region
• Gas flow models in the Milky Way embedded bars
• Stellar Proper Motions in the Galactic Bulge from deep HST ACS/WFC Photometry
• Dynamical masses of early-type galaxies at z~2: Are they truly superdense?
• ARGOS II: The Galactic Bulge Survey
• NMAGIC: Fast Parallel Implementation of a Chi-Squared-Made-to-Measure Algorithm for Modelling Observational Data
• The Bulge Radial Velocity Assay (BRAVA): I. Techniques and a Rotation Curve
• 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
• The Bulge Radial Velocity Assay (BRAVA): I. Sample Selection and a Rotation Curve
• Model-based pattern speed estimates for 38 barred galaxies
• Dark matter content and internal dynamics of NGC 4697: NMAGIC particle models from slit data and planetary nebulae velocities
• The long Galactic bar as seen by UKIDSS Galactic Plane Survey
• Peanuts, brezels and bananas: food for thought on the orbital structure of the Galactic bulge
• MOA-II Galactic Microlensing Constraints: The Inner Milky Way has a Low Dark Matter Fraction and a Near Maximal Disk
• Why the Milky Way's bulge is not only a bar formed from a cold thin disk
• The incorrect rotation curve of the Milky Way
• The Next Generation Virgo cluster Survey. V. modelling the dynamics of M87 with the Made-to-Measure method
• Proper Motion Dispersions of Red Clump Giants in the Galactic Bulge: Observations and Model Comparisons
• A bar in the inner halo of barred galaxies I. Structure and kinematics of a representative model
• The Stellar Halo in the Inner Milky Way: Predicted Shape and Kinematics

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• Globular clusters in the inner Galaxy classified from dynamical orbital criteria
• Exploring the stellar age distribution of the Milky Way Bulge using APOGEE
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• The Hercules stream as seen by APOGEE-2 South
• The Initial Mass Function of the Inner Galaxy Measured From OGLE-III Microlensing Timescales
• Quantifying the (X/peanut)-shaped Structure of the Milky Way - New Constraints on the Bar Geometry
• Exploring the origin of moving groups and diagonal ridges by simulations of stellar orbits and birthplaces
• Testing the Prediction of Fuzzy Dark Matter Theory in the Milky Way Center
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• The vertical Na-O relation in the bulge globular cluster NGC 6553
• Was the Milky Way Bulge Formed From The Buckling Disk Instability, Hierarchical Collapse, Accretion of Clumps, or All of the Above?
• The Imprint of Spiral Arms on the Galactic Rotation Curve
• 7.1 keV sterile neutrino dark matter constraints from a deep Chandra X-ray observation of the Galactic bulge Limiting Window
• The Quintuplet Cluster: Extended Structure and Tidal Radius
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• New insights in the origin and evolution of the old, metal-rich open cluster NGC 6791
• Self-consistent bulge/disk/halo galaxy dynamical modeling using integral field kinematics
• Inverse Compton emission from millisecond pulsars in the Galactic bulge
• Intermediate mass black holes and dark matter at the Galactic center
• The dynamics of Galactic centre pulsars: constraining pulsar distances and intrinsic spin-down
• Axial Asymmetry Studies in Gaia Data Release 2 Yield the Pattern Speed of the Galactic Bar