Sizing from the Smallest Scales: The Mass of the Milky Way

Abstract

As the Milky Way and its satellite system become more entrenched in near field cosmology efforts, the need for an accurate mass estimate of the Milky Way's dark matter halo is increasingly critical. With the second and early third data releases of stellar proper motions from {\it Gaia}, several groups calculated full $6$D phase-space information for the population of Milky Way satellite galaxies. Utilizing these data in comparison to subhalo properties drawn from the Phat ELVIS simulations, we constrain the Milky Way dark matter halo mass to be $\sim 1-1.2\times10^{12}~\msun$. We find that the kinematics of subhalos drawn from more- or less-massive hosts (i.e. $>1.2\times10^{12}~\msun$ or $<10^{12}~\msun$) are inconsistent, at the $3\sigma$ confidence level, with the observed velocities of the Milky Way satellites. The preferred host halo mass for the Milky Way is largely insensitive to the exclusion of systems associated with the Large Magellanic Cloud, changes in galaxy formation thresholds, and variations in observational completeness. As more Milky Way satellites are discovered, their velocities (radial, tangential, and total) plus Galactocentric distances will provide further insight into the mass of the Milky Way dark matter halo.

Key Figures: 4 and 5; 15 pages; 8 figures; accepted for publication in MNRAS 3 May 2022

References in corpus (55)

• Array Programming with NumPy
• The Gaia mission
• galpy: A Python Library for Galactic Dynamics
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function
• The Milky Way total mass profile as inferred from Gaia DR2
• "Skinny Milky Way, Please", says Sagittarius
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• The SAGA Survey. II. Building a Statistical Sample of Satellite Systems around Milky Way-like Galaxies
• The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions
• The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s
• The Invisibles: A Detection Algorithm to Trace the Faintest Milky Way Satellites
• Milky Way Satellite Census. I. The Observational Selection Function for Milky Way Satellites in DES Y3 and Pan-STARRS DR1
• Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
• The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites
• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• The Space Motion of Leo I: Hubble Space Telescope Proper Motion and Implied Orbit
• The mass of our Milky Way
• Shaken and Stirred: The Milky Way's Dark Substructures
• The Milky Way's Disk of Classical Satellite Galaxies in Light of Gaia DR2
• A thousand shadows of Andromeda: rotating planes of satellites in the Millennium-II cosmological simulation
• The Araucaria Project. The Distance to the Sculptor dwarf spheroidal galaxy from infrared photometry of RR Lyrae stars
• Too Many, Too Few, or Just Right? The Predicted Number and Distribution of Milky Way Dwarf Galaxies
• Variable stars in the newly discovered Milky Way satellite in Bootes
• Revised and new proper motions for confirmed and candidate Milky Way dwarf galaxies
• Gaia EDR3 proper motions of Milky Way dwarfs I: 3D Motions and Orbits
• The Variable Stars of the Draco Dwarf Spheroidal Galaxy - Revisited
• Planes of satellites around Milky Way/M31-mass galaxies in the FIRE simulations and comparisons with the Local Group
• The distance to the Fornax Dwarf Spheroidal Galaxy
• Milky Way mass constraints from the Galactic satellite gap
• Variable Stars in the Newly Discovered Milky Way Dwarf Spheroidal Satellite Canes Venatici I
• The Leo IV dwarf spheroidal galaxy: color-magnitude diagram and pulsating stars
• Equilibrium models of the Milky Way mass are biased high by the LMC
• On the newly discovered Canes Venatici II dSph galaxy
• The Edge of the Galaxy
• The mass of our Galaxy from satellite proper motions in the Gaia era
• Constraining the Milky Way Mass Profile with Phase-Space Distribution of Satellite Galaxies
• Comparing the observable properties of dwarf galaxies on and off the Andromeda plane
• Bootes II ReBooted: An MMT/MegaCam Study of An Ultra-Faint Milky Way Satellite
• Can cosmological simulations capture the diverse satellite populations of observed Milky Way analogues?
• Pulsating Variable Stars in the Coma Berenices dwarf spheroidal galaxy
• Radial Distributions of Dwarf Satellite Systems in the Local Volume
• Evolution of galactic planes of satellites in the EAGLE simulation
• The little things matter: relating the abundance of ultrafaint satellites to the hosts' assembly history
• The Role of Baryons in Creating Statistically Significant Planes of Satellites around Milky Way-Mass Galaxies
• Deep Subaru Hyper Suprime-Cam observations of Milky Way satellites Columba I and Triangulum II
• Magellanic satellites in $\Lambda$CDM cosmological hydrodynamical simulations of the Local Group
• Co-orbiting planes of sub-halos are similarly unlikely around paired and isolated hosts
• The infall of dwarf satellite galaxies are influenced by their host's massive accretions
• A Lower Limit on the Mass of Our Galaxy from the H3 Survey
• The Local Group as a test system for Modified Newtonian Dynamics

Cited by in corpus (4)

• Milky Way Mass with K Giants and BHB Stars Using LAMOST, SDSS/SEGUE, and Gaia: 3D Spherical Jeans Equation and Tracer Mass Estimator
• The Local Group's mass: probably no more than the sum of its parts
• Determining Satellite Infall Times Using Machine Learning
• Weighing the Milky Way and Andromeda with Artificial Intelligence