Kinematics of the stellar halo and the mass distribution of the Milky Way using BHB stars

Abstract

Here we present a kinematic study of the Galactic halo out to a radius of $\sim$ 60 kpc, using 4664 blue horizontal branch (BHB) stars selected from the SDSS/SEGUE survey, to determine key dynamical properties. Using a maximum likelihood analysis, we determine the velocity dispersion profiles in spherical coordinates (${\sigma }_r$, ${\sigma }_{\theta }$, ${\sigma }_{\varphi }$) and the anisotropy profile ($\beta$). The radial velocity dispersion profile (${\sigma }_r$) is measured out to a galactocentric radius of $r\sim 60$ kpc, but due to the lack of proper-motion information, ${\sigma }_{\theta }$, ${\sigma }_{\varphi }$ and $\beta$ could only be derived directly out to $r\sim 25$ kpc. From a starting value of $\beta \approx 0.5$ in the inner parts ($9<r/\kpc<12$), the profile falls sharply in the range $r\approx 13-18$ kpc, with a minimum value of $\beta =-1.2$ at $r=17$ kpc, rising sharply at larger radius. In the outer parts, in the range $25<r/\kpc<56$, we predict the profile to be roughly constant with a value of $\beta \approx 0.5$. The newly discovered kinematic anomalies are shown not to arise from halo substructures. We also studied the anisotropy profile of simulated stellar halos formed purely by accretion and found that they cannot reproduce the sharp dip seen in the data. From the Jeans equation, we compute the stellar rotation curve ($v_{\mathrm{circ}}$) of the Galaxy out to $r\sim 25$ kpc. The mass of the Galaxy within $r\lesssim 25$ kpc is determined to be $2.1\times 10^{11}$ $M_{\sun}$, and with a 3-component fit to $v_{\mathrm{circ}}(r)$, we determine the virial mass of the Milky Way dark matter halo to be $M_{\mathrm{vir}}=0.9_{-0.3}^{+0.4}\times 10^{12}$ $M_{\sun}$ ($R_{\mathrm{vir}}=249_{-31}^{+34}$ kpc).

arXiv commentAccepted for Publication in ApJ, uses emulateapj.sty,19 pages, 17 figures

References in corpus (83)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The Structure of Cold Dark Matter Halos
• The Seventh Data Release of the Sloan Digital Sky Survey
• Statistical Properties of X-ray Clusters: Analytic and Numerical Comparisons
• Local Kinematics and the Local Standard of Rest
• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way
• SEGUE: A Spectroscopic Survey of 240,000 stars with g=14-20
• The New Galaxy: Signatures of its Formation
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• Tracing Galaxy Formation with Stellar Halos I: Methods
• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• The Field of Streams: Sagittarius and its Siblings
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• SINFONI in the Galactic Center: young stars and IR flares in the central light month
• The RAVE Survey: Constraining the Local Galactic Escape Speed
• Two Stellar Components in the Halo of the Milky Way
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• Concentration, Spin and Shape of Dark Matter Haloes: Scatter and the Dependence on Mass and Environment
• LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The survey science plan
• Structure and Kinematics of the Stellar Halos and Thick Disks of the Milky Way Based on Calibration Stars from SDSS DR7
• Building up the Stellar Halo of the Galaxy
• The accretion origin of the Milky Way's stellar halo
• Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream
• Tracing Galaxy Formation with Stellar Halos II: Relating Substructure in Phase- and Abundance-Space to Accretion Histories
• The Present and Future Mass of the Milky Way Halo
• Sagittarius: The Nearest Dwarf Galaxy
• The Masses of the Milky Way and Andromeda galaxies
• The Dual Origin of Stellar Halos
• Galaxia: a code to generate a synthetic survey of the Milky Way
• Unified Rotation Curve of the Galaxy -- Decomposition into de Vaucouleurs Bulge, Disk, Dark Halo, and the 9-kpc Rotation Dip --
• The Milky Way stellar halo out to 40 kpc : Squashed, broken but smooth
• Cosmological simulations of the formation of the stellar haloes around disc galaxies
• The radial velocity dispersion profile of the Galactic halo: Constraining the density profile of the dark halo of the Milky Way
• Stars beyond Galaxies: The Origin of Extended Luminous Halos around Galaxies
• Substructure revealed by RR Lyraes in SDSS Stripe 82
• The stellar halo of the Galaxy
• Masses for the Local Group and the Milky Way
• Mapping the stellar structure of the Milky Way thick disk and halo using SEGUE photometry
• The Milky Way Tomography with SDSS: III. Stellar Kinematics
• The uncertainty in Galactic parameters
• The Mass of the Milky Way: Limits from a Newly Assembled Set of Halo Objects
• The Mass of the Milky Way Galaxy
• Exploring Halo Substructure with Giant Stars: A diffuse star cloud or tidal debris around the Milky Way in Triangulum-Andromeda
• Galactic masers and the Milky Way circular velocity
• The Case for the Dual Halo of the Milky Way
• Quantifying Kinematic Substructure in the Milky Way's Stellar Halo
• Kinematics of SDSS subdwarfs: Structure and substructure of the Milky Way halo
• The Mass Profile of the Galaxy to 80 kpc
• Blue horizontal branch stars in the Sloan Digital Sky Survey: I. Sample selection and structure in the Galactic halo
• Global structure and kinematics of stellar haloes in cosmological hydrodynamic simulations
• Astrometry of Galactic Star Forming Region Sharpless 269 with VERA : Parallax Measurements and Constraint on Outer Rotation Curve
• The cold veil of the Milky Way stellar halo
• The velocity dispersion and mass profile of the Milky Way
• First Determination of the Distance and Fundamental Properties of an Eclipsing Binary in The Andromeda Galaxy
• Broken degeneracies: the rotation curve and velocity anisotropy of the Milky Way halo
• Refining the Oort and Galactic constants
• Satellites of Simulated Galaxies: survival, merging, and their relation to the dark and stellar halos
• Detection of the Main Sequence Turn-off of a Newly Discovered Milky Way Halo Structure in the Triangulum-Andromeda Region
• Discovery of Andromeda XIV: A Dwarf Spheroidal Dynamical Rogue in the Local Group?
• The Age of the Milky Way Inner Halo
• Rotation of Halo Populations in the Milky Way and M31
• On the alleged duality of the Galactic halo
• Velocity Dispersion Profile of the Milky Way Halo
• Galactic halo stellar structures in the Triangulum-Andromeda region
• Blue horizontal branch stars in the Sloan Digital Sky Survey: II. Kinematics of the Galactic halo
• A Revised LCDM Mass Model For The Andromeda Galaxy
• Dynamical models with a general anisotropy profile
• The Tilt of the Halo Velocity Ellipsoid and the Shape of the Milky Way Halo
• A dynamical and kinematical model of the Galactic stellar halo and possible implications for galaxy formation scenarios
• The Hernquist model revisited: completely analytical anisotropic dynamical models
• Simple Three-Integral Scale-Free Galaxy Models
• The Kinematic Properties of BHB and RR Lyrae stars towards the Anticentre and the North Galactic Pole: The Transition between the Inner and the Outer Halo
• Kinematic Structure in the Galactic Halo at the North Galactic Pole: RR Lyrae and BHB Stars show different kinematics
• On the Keplerian Rotation Curves of Galaxies
• A large local rotational speed for the Galaxy found from proper-motions: Implications for the mass of the Milky-Way
• Mapping the Galactic Halo with blue horizontal branch stars from the 2dF quasar redshift survey
• Group Finding in the Stellar Halo using Photometric Surveys: Current Sensitivity and Future Prospects
• On the Adromeda to Milky Way mass-ratio

Cited by in corpus (132)

• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• Co-formation of the Galactic disc and the stellar halo
• Beyond Collisionless Dark Matter: Particle Physics Dynamics for Dark Matter Halo Structure
• The Circular Velocity Curve of the Milky Way from $5$ to $25$ kpc
• Evidence from the H3 Survey that the Stellar Halo is Entirely Comprised of Substructure
• The Dark Matter Halo of the Milky Way, AD 2013
• The Milky Way total mass profile as inferred from Gaia DR2
• The RAVE survey: the Galactic escape speed and the mass of the Milky Way
• Markov Chain Monte Carlo Methods for Bayesian Data Analysis in Astronomy
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• The Milky Way's rotation curve out to 100 kpc and its constraint on the Galactic mass distribution
• Globular Cluster Streams as Galactic High-Precision Scales - The Poster Child Palomar 5
• The mass of the Milky Way from satellite dynamics
• Evidence for an Intermediate-Mass Milky Way from Gaia DR2 Halo Globular Cluster Motions
• Ages and kinematics of chemically selected, accreted Milky Way halo stars
• Rotation Curve of the Milky Way out to $\sim$ 200 kpc
• From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity
• The shape of the Galactic halo with $Gaia$ DR2 RR Lyrae. Anatomy of an ancient major merger
• The mass of our Milky Way
• Testing Einstein's Equivalence Principle with Fast Radio Bursts
• Estimating the dark matter halo mass of our Milky Way using dynamical tracers
• Exploring the Variable Sky with LINEAR. II. Halo Structure and Substructure Traced by RR Lyrae Stars to 30 kpc
• Limits on Pop III star formation with the most iron-poor stars
• Hints on the Nature of Dark Matter from the Properties of Milky Way Satellites
• The Halo's Ancient Metal-Rich Progenitor Revealed with BHB Stars
• RR Lyrae variables: visual and infrared luminosities, intrinsic colours, and kinematics
• Stellar labels for hot stars from low-resolution spectra - I. the HotPayne method and results for 330,000 stars from LAMOST DR6
• Fossil imprint of a powerful flare at the Galactic Centre along the Magellanic Stream
• The cumulative mass profile of the Milky Way as determined by globular cluster kinematics from Gaia DR2
• Expanded haloes, abundance matching and too-big-to-fail in the Local Group
• The Circular Velocity Curve of the Milky Way from 5 to 25 kpc using luminous red giant branch star
• Galactic Archaeology with Gaia
• The Need for Speed: Escape velocity and dynamical mass measurements of the Andromeda galaxy
• Baryonic and dark matter distribution in cosmological simulations of spiral galaxies
• Mapping the Milky Way Disk with Gaia DR3: 3D extended kinematic maps and rotation curve to $\approx 30$ kpc
• Cosmic Transients Test Einstein's Equivalence Principle out to GeV Energies
• Prospects for chemically tagging stars in the Galaxy
• The Rotation Curve, Mass Distribution and Dark Matter Content of the Milky Way from Classical Cepheids
• Characterising stellar halo populations I: An extended distribution function for halo K giants
• Action-space clustering of tidal streams to infer the Galactic potential
• Anisotropy of the Milky Way's stellar halo using K giants from LAMOST and $Gaia$
• Assessing Astrophysical Uncertainties in Direct Detection with Galaxy Simulations
• The Velocity Anisotropy of Distant Milky Way Halo Stars from Hubble Space Telescope Proper Motions
• A robust estimate of the Milky Way mass from rotation curve data
• Bayesian Mass Estimates of the Milky Way II: The dark and light sides of parameter assumptions
• Estimating the Mass of the Milky Way Using the Ensemble of Classical Satellite Galaxies
• Testing Einstein's Weak Equivalence Principle With Gravitational Waves
• Connecting Direct Dark Matter Detection Experiments to Cosmologically Motivated Halo Models
• Constraining dark matter annihilation with the isotropic $\gamma$-ray background: updated limits and future potential
• Constraints on the assembly history of the Milky Way's smooth, diffuse stellar halo from the metallicity-dependent, radially-dominated velocity anisotropy profiles probed with K giants and BHB stars using LAMOST, SDSS/SEGUE, and Gaia
• Rotation Curve and Mass Distribution in the Galaxy from the Velocities of Objects at Distances up to 200 kpc
• Dynamical Evidence of a Solitonic Core of $10^9{M}_{\odot }$ in the Milky Way
• Haloes light and dark: dynamical models of the stellar halo and constraints on the mass of the Galaxy
• Origin of the Local Group satellite planes
• A "Light," Centrally-Concentrated Milky Way Halo?
• Characterizing stellar halo populations II: The age gradient in blue horizontal-branch stars
• A Genetic Approach to the History of the Magellanic Clouds
• Tests of the Einstein Equivalence Principle using TeV Blazars
• Milky Way total Mass derived by Rotation Curve and Globular Cluster kinematics from Gaia EDR3
• Milky Way Mass with K Giants and BHB Stars Using LAMOST, SDSS/SEGUE, and Gaia: 3D Spherical Jeans Equation and Tracer Mass Estimator
• Introducing galactic structure finder: the multiple stellar kinematic structures of a simulated Milky Way mass galaxy
• On the stark difference in satellite distributions around the Milky Way and Andromeda
• Metallicity Bias in the Kinematics of the Milky Way Stellar Halo
• Orbital anisotropy in cosmological haloes revisited
• Gaia-DR2 extended kinematical maps. Part I: Method and application
• Very Metal-Poor Outer-Halo Stars with Round Orbits
• The Saga of M81: Global View of a Massive Stellar Halo in Formation
• Satellites in MW-like hosts: Environment dependence and close pairs
• Multimessenger tests of the weak equivalence principle from GW170817 and its electromagnetic counterparts
• Limits on the Weak Equivalence Principle and Photon Mass with FRB 121102 Sub-pulses
• A Plane of High Velocity Galaxies Across the Local Group
• Global Properties of M31's Stellar Halo from the SPLASH Survey: III. Measuring the Stellar Velocity Dispersion Profile
• Bayesian Mass Estimates of the Milky Way: including measurement uncertainties with hierarchical Bayes
• Identifying RR Lyrae Variable Stars in Six Years of the Dark Energy Survey
• HALO7D II: The Halo Velocity Ellipsoid and Velocity Anisotropy with Distant Main Sequence Stars
• The proper motion of Palomar 5
• A New Signal Model for Axion Cavity Searches from N-Body Simulations
• Figuring Out Gas & Galaxies in Enzo (FOGGIE). III. The Mocky Way: Investigating Biases in Observing the Milky Way's Circumgalactic Medium
• The Escape Velocity Curve of the Milky Way in Modified Newtonian Dynamics
• Stellar Velocity Dispersion and Anisotropy of the Milky Way Inner Halo
• Beta Dips in the Gaia Era: Simulation Predictions of the Galactic Velocity Anisotropy Parameter for Stellar Halos
• Constraints from the Time Lag between Gravitational Waves and Gamma Rays: Implications of GW 170817 and GRB 170817A
• Chemical Cartography. II. The Assembly History of the Galactic Stellar Halo Traced by Carbon-Enhanced Metal-Poor Stars
• $\text{galkin}$: a new compilation of the Milky Way rotation curve data
• Isotropic at the Break? 3D Kinematics of Milky Way Halo Stars in the Foreground of M31
• The Milky Way's circular velocity curve and its constraint on the Galactic mass with RR Lyrae stars
• The SLUGGS Survey: Multi-population dynamical modelling of the elliptical galaxy NGC 1407 from stars and globular clusters
• Revealing the Ionization Properties of the Magellanic Stream using Optical Emission
• What to expect from dynamical modelling of galactic haloes II: the spherical Jeans equation
• GARROTXA Cosmological Simulations of Milky Way-sized Galaxies: General Properties, Hot Gas Distribution, and Missing Baryons
• Probing Dark Matter Using Precision Measurements of Stellar Accelerations
• Contribution of Gaia Sausage to the Galactic Stellar Halo Revealed by K Giants and Blue Horizontal Branch Stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, Sloan Digital Sky Survey, and Gaia
• Spitzer, Gaia, and the Potential of the Milky Way
• Cosmological simulations of the same spiral galaxy: the impact of baryonic physics
• Impact of the Galactic Disk and Large Magellanic Cloud on the Trajectories of Hypervelocity Stars Ejected from the Galactic Center
• Gas-phase oxygen abundances and radial metallicity gradients in the two nearby spiral galaxies NGC7793 and NGC4945
• The oblateness of the Milky Way dark matter halo from the stellar streams of NGC 3201, M68, and Palomar 5
• Probing the Galactic halo with RR Lyrae stars $-$ III. The chemical and kinematic properties of the stellar halo
• Systematic uncertainties from halo asphericity in dark matter searches
• The nature of the Milky Way's stellar halo revealed by the three integrals of motion
• Galactic googly: the rotation-metallicity bias in the inner stellar halo of the Milky Way
• Classifying globular clusters and applying them to estimate the mass of the Milky Way
• Halo orbits in cosmological disk galaxies: tracers of formation history
• The Milky Way and Andromeda galaxies in a constrained hydrodynamical simulation: morphological evolution
• Dynamical History of the Local Group in $\Lambda$CDM
• The SLUGGS Survey: The Inner Dark Matter Density Slope of the Massive Elliptical Galaxy NGC 1407
• Orbits of globular clusters computed with dynamical friction in the Galactic anisotropic velocity dispersion field
• The effect of gravitational tides on dwarf spheroidal galaxies
• The giants that were born swiftly -- Implications of the top-heavy stellar initial mass function on the birth conditions of globular clusters
• Dynamical History Of The Local Group In $\Lambda$CDM $\mathrm{II}$ $-$ Including External Perturbers In 3D
• Test of the Weak Equivalence Principle using LIGO observations of GW150914 and Fermi observations of GBM transient 150914
• GRBs and fundamental physics
• Reliability of the measured velocity anisotropy of the Milky Way stellar halo
• On the absence of backsplash analogues to NGC 3109 in the $\Lambda$CDM framework
• The local rotation curve of the Milky Way based on SEGUE and RAVE data
• Galacto-forensic of LMC's orbital history as a probe for the dark matter potential in the outskirt of the Galaxy
• Jeans that fit: weighing the mass of the Milky Way analogues in the $\Lambda \mathrm{CDM}$ universe
• On the origin of the asymmetric dwarf galaxy distribution around Andromeda
• Isothermal distributions in MONDian gravity as a simple unifying explanation for the ubiquitous $\rho \propto r^{-3}$ density profiles in tenuous stellar halos
• The Effect of the Remnant Mass in Estimating Stellar Mass of Galaxies
• On the robustness of the velocity anisotropy parameter in probing the stellar kinematics in Milky Way like galaxies: Take away from TNG50 simulation
• Fading Features Found in the Kinematics of the Far-Reaching Milky Way Stellar Halo
• Astrometric test of the weak equivalence principle
• Galactic cartography with SkyMapper: I. Population sub-structure and the stellar number density of the inner halo
• Line-of-sight mass estimator and the masses of the Milky Way and Andromeda Galaxy
• Dark matter effect attributed to the inherent structure of cosmic space
• Effect of dynamical interactions on integrated properties of globular clusters
• The optimisation of low-acceleration interstellar relativistic rocket trajectories using genetic algorithms
• The Outer Galactic Halo As Probed By RR Lyr Stars From the Palomar Transient Facility + Keck
• DELVE-ing into the Milky Way's Globular Clusters: Assessing extra-tidal features in NGC 5897, NGC 7492, and testing detectability with deeper photometry
• Metallicity Structure in Galactic Longitude-Velocity Diagrams of the Milky Way Disk and FIRE-2 Simulations
• Anisotropy of Halo Main Sequence Turnoff Stars Measured with New MMT Radial Velocities and Gaia Proper Motions