Detecting the Figure Rotation of Dark Matter Halos with Tidal Streams

Abstract

The dark matter halos that surround Milky Way-like galaxies in cosmological simulations are, to first order, triaxial. Nearly 30 years ago it was predicted that such triaxial dark matter halos should exhibit steady figure rotation or tumbling motions for durations of several gigayears. The angular frequency of figure rotation predicted by cosmological simulations is described by a log-normal distribution of pattern speed with a median value 0.15hkm/s/kpc (~ 0.15h rad/Gyr ~ 9h deg/Gyr) and a width of 0.83km/s/kpc. These pattern speeds are so small that they have generally been considered both unimportant and undetectable. In this work we show that even this extremely slow figure rotation can significantly alter the structure of extended stellar streams produced by the tidal disruption of satellites in the Milky Way halo. We simulate the behavior of a Sagittarius-like polar tidal stream in triaxial dark matter halos with different shapes, when the halos are rotated about the three principal axes. For pattern speeds typical of cosmological halos we demonstrate, for the first time, that a Sagittarius-like tidal stream would be altered to a degree that is detectable even with current observations. This discovery will potentially allow for a future measurement of figure rotation of the Milky Way's dark halo, and perhaps enabling the first evidence of this relatively unexplored prediction of LambdaCDM.

arXiv comment23 pages, 10 figures, accepted for publication in the Astrophysical Journal. Revised version includes a new subsection on the generalized effects of figure rotation about any of the 3 principle axes of triaxial potential on both long and short axis tubes

References in corpus (71)

• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• A Universal Density Profile from Hierarchical Clustering
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• The DESI Experiment Part I: Science,Targeting, and Survey Design
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• MultiDark simulations: the story of dark matter halo concentrations and density profiles
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• 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
• Cosmological Simulations with Self-Interacting Dark Matter II: Halo Shapes vs. Observations
• Density Profiles of Dark Matter Halo are not Universal
• The Effect of Gas Cooling on the Shapes of Dark Matter Halos
• Tango for three: Sagittarius, LMC, and the Milky Way
• Stellar Streams Discovered in the Dark Energy Survey
• Simulations of the Magellanic Stream in a First Infall Scenario
• The Origin of the Bifurcation in the Sagittarius Stream
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: III. Constraints on the Flattening of the Galactic Halo
• The Influence of Sagittarius and the Large Magellanic Cloud on the Milky Way Galaxy
• Precession of the Sagittarius stream
• Tidal Streams as Probes of the Galactic Potential
• Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud
• 4MOST - 4-metre Multi-Object Spectroscopic Telescope
• The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks Versus Substructures
• And yet it moves: The dangers of artificially fixing the Milky Way center of mass in the presence of a massive Large Magellanic Cloud
• The Sagittarius Streams in the Southern Galactic Hemisphere
• More on the structure of tidal tails
• A Two Micron All-Sky Survey View of the Sagittarius Dwarf Galaxy: II. Swope Telescope Spectroscopy of M Giant Stars in the Dynamically Cold Sagittarius Tidal Stream
• Constraints on the shape of the Milky Way dark matter halo from the Sagittarius stream
• The COpernicus COmplexio: Statistical Properties of Warm Dark Matter Haloes
• Was the Progenitor of the Sagittarius Stream a Disc Galaxy?
• Shape of Dark Matter Haloes in the Illustris Simulation: Effects of Baryons
• Is the dark halo of our Galaxy spherical?
• Generation of mock tidal streams
• The last breath of the Sagittarius dSph
• A Tail of Two Populations: Chemo-dynamics of the Sagittarius Stream and Implications for its Original Mass
• The Orbit and Mass of the Sagittarius Dwarf Galaxy
• Tracing the Outer Structure of the Sagittarius Dwarf Galaxy: Detections at Angular Distances Between 10 and 34 Degrees
• Project overview and update on WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope
• The Shape and Figure Rotation of NGC 2915's Dark Halo
• Chaotic Dispersal of Tidal Debris
• Modeling Intra-Cluster Gas in Triaxial Dark Halos : An Analytical Approach
• What's Up in the Milky Way? The Orientation of the Disc Relative to the Triaxial Halo
• Predicted Extension of the Sagittarius Stream to the Milky Way Virial Radius
• The Sagittarius Stream and Halo Triaxiality
• The impact of baryon physics on the structure of high-redshift galaxies
• The Geometry of Sagittarius Stream from Pan-STARRS1 3$\pi$ RR Lyrae
• An all-sky proper motion map of the Sagittarius stream using Gaia DR2
• Warps and Bars from the External Tidal Torques of Tumbling Dark Halos
• A unified framework for the orbital structure of bars and triaxial ellipsoids
• Kinematics and Chemistry of Stars Along the Sagittarius Trailing Tidal Tail and Constraints on the Milky Way Mass Distribution
• MOND vs. dark matter in light of historical parallels
• Old, Metal-Poor Extreme Velocity Stars in the Solar Neighborhood
• Locating the orbits delineated by tidal streams
• A Pan-STARRS1 View of the Bifurcated Sagittarius Stream
• Figure Rotation of Cosmological Dark Matter Halos
• Extended HI spiral structure and the figure rotation of triaxial dark halos
• The Gaia inertial reference frame and the tilting of the Milky Way disk
• Connecting the Milky Way potential profile to the orbital timescales and spatial structure of the Sagittarius Stream
• Upper Limit on the Milky Way Mass from the Orbit of the Sagittarius Dwarf Satellite
• Orbital Instabilities in a Triaxial Cusp Potential
• On the Spiral Structure of NGC 2915 and Dark Matter
• Hubble Space Telescope Proper Motions along the Sagittarius Stream: I. Observations and Results for Stars in Four Fields
• The Orbital Structure of Triaxial Galaxies with Figure Rotation
• Hubble Space Telescope Proper Motions of Individual Stars in Stellar Streams: Orphan, Sagittarius, Lethe, and the New "Parallel" Stream
• Figure rotation of dark halos in CDM simulations
• The tilting rate of the Milky Way's disc
• Drivers of disc tilting I: Correlations and possible drivers for Milky Way analogues

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