Is the vast polar structure of dwarf galaxies a serious problem for lambda cold dark matter?

Abstract

The dwarf galaxies around the Milky Way are distributed in a so-called vast polar structure (VPOS) that may be in conflict with Lambda CDM simulations. Here, we seek to determine if the VPOS poses a serious challenge to the Lambda cold dark matter paradigm on galactic scales. Specifically, we investigate if the VPOS remains coherent as a function of time. Using the measured Hubble Space Telescope (HST) proper motions and associated uncertainties, we integrate the orbits of the classical Milky Way satellites backwards in time and find that the structure disperses well before a dynamical time. We also examine in particular Leo I and Leo II using their most recent proper motion data, both of which have extreme kinematic properties, but these satellites do not appear to drive the polar fit that is seen at the present day. We have studied the effect of the uncertainties on the HST proper motions on the coherence of the VPOS as a function of time. We find that 8 of the 11 classical dwarfs have reliable proper motions; for these 8, the VPOS also loses significance in less than a dynamical time, indicating that the VPOS is not a dynamically stable structure. Obtaining more accurate proper motion measurements of Ursa Minor, Sculptor, and Carina would bolster these conclusions.

arXiv comment14 pages, 6 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society. Replacement: expanded discussion, grammar corrected, accepted version of text

References in corpus (70)

• The cosmological simulation code GADGET-2
• Dark Matter Substructure in Galactic Halos
• Where are the missing galactic satellites?
• Dwarf Galaxies of the Local Group
• The observed properties of dwarf galaxies in and around the Local Group
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• Gasoline: An adaptable implementation of TreeSPH
• A Universal Mass Profile for Dwarf Spheroidal Galaxies?
• The tumultuous lives of galactic dwarfs and the missing satellites problem
• The APOSTLE simulations: solutions to the Local Group's cosmic puzzles
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• The Sagittarius Dwarf Galaxy: a Model for Evolution in a Triaxial Milky Way Halo
• Forming Realistic Late-Type Spirals in a LCDM Universe: The Eris Simulation
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• Dark matter substructure and gamma-ray annihilation in the Milky Way halo
• Halo Substructure And The Power Spectrum
• The great disk of Milky-Way satellites and cosmological sub-structures
• The Masses of the Milky Way and Andromeda galaxies
• ELVIS: Exploring the Local Volume in Simulations
• The Anisotropic Distribution of Galactic Satellites
• The Sagittarius impact as an architect of spirality and outer rings in the Milky Way
• Local-Group tests of dark-matter Concordance Cosmology: Towards a new paradigm for structure formation
• The Velocity Dispersion Profile of the Remote Dwarf Spheroidal Galaxy Leo I: A Tidal Hit and Run?
• The Space Motion of Leo I: The Mass of the Milky Way's Dark Matter Halo
• The spatial distribution of the Milky Way and Andromeda satellite galaxies
• The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks Versus Substructures
• The Missing Massive Satellites of the Milky Way
• The rotationally stabilized VPOS and predicted proper motions of the Milky Way satellite galaxies
• Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
• The Three-Dimensional Structure of the M31 Satellite System; Strong Evidence for an Inhomogeneous Distribution of Satellites
• The Space Motion of Leo I: Hubble Space Telescope Proper Motion and Implied Orbit
• Broken degeneracies: the rotation curve and velocity anisotropy of the Milky Way halo
• Planes of satellite galaxies and the cosmic web
• The vast thin plane of M31 co-rotating dwarfs: an additional fossil signature of the M31 merger and of its considerable impact in the whole Local Group
• Estimating the dark matter halo mass of our Milky Way using dynamical tracers
• Satellites of Simulated Galaxies: survival, merging, and their relation to the dark and stellar halos
• Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. IV: Measurement for Sculptor
• Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. V: Final Measurement for Fornax
• The Observed and Predicted Spatial Distribution of Milky Way Satellite Galaxies
• Planes of satellite galaxies: when exceptions are the rule
• Constraining the History of the Sagittarius Dwarf Galaxy Using Observations of its Tidal Debris
• The universal nature of subhalo accretion
• Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. III: Measurement for Ursa Minor
• On the Distribution of Orbital Poles of Milky Way Satellites
• Satellite Systems around Galaxies in Hydrodynamic Simulations
• Are Great Disks Defined by Satellite Galaxies in Milky-Way Type Halos Rare in $\Lambda$CDM model?
• Large-scale mass distribution in the Illustris simulation
• The Formation of the Local Group Planes of Galaxies
• The survival of the Sgr dwarf galaxy and the flatness of the rotation curve of the Galaxy
• The Spatial Distribution of Galactic Satellites in the LCDM Cosmology
• What's Up in the Milky Way? The Orientation of the Disc Relative to the Triaxial Halo
• HST absolute Proper Motions of NGC 6681 (M70) and the Sagittarius Dwarf Spheroidal Galaxy
• Alignments between galaxies, satellite systems and haloes
• Inferring the gravitational potential of the Milky Way with a few precisely measured stars
• Comparing the observable properties of dwarf galaxies on and off the Andromeda plane
• The Role of Gas In Maintaining Quasi-Steady Spiral Structure In Stellar Disks
• A Council of Giants
• Simulated ΛCDM analogues of the thin Plane of Satellites around the Andromeda galaxy are not kinematically coherent structures
• The Role of Baryons in Creating Statistically Significant Planes of Satellites around Milky Way-Mass Galaxies
• On the stark difference in satellite distributions around the Milky Way and Andromeda
• On the Stability of Satellite Planes I: Effects of Mass, Velocity, Halo Shape and Alignment
• Tidal Imprints of a Dark Sub-Halo on the Outskirts of the Milky Way II. Perturber Azimuth
• Local Group galaxies emerge from the dark
• Incorporating Streams into Milky Way Models
• Proper Motion of the Draco Dwarf Galaxy from Subaru Suprime-Cam Data
• An Eccentricity-Mass Relation for Galaxies from Tidally Disrupting Satellites
• Galactoseismology: Discovery of a cluster of receding, variable halo stars

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• Evolution of galactic planes of satellites in the EAGLE simulation
• The twisted dark matter halo of the Milky Way
• Antlia2's role in driving the ripples in the outer gas disk of the Galaxy
• Stability of Satellite Planes in M31 II: Effects of the Dark Subhalo Population
• Is there a disk of satellites around the Milky Way?
• Planes of satellites around simulated disk galaxies II: Time-persistent planes of kinematically-coherent satellites in $\Lambda$CDM
• VALES V: A kinematic analysis of the molecular gas content in $H$-ATLAS galaxies at $z\sim 0.03-0.35$ using ALMA
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