The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites

Abstract

A significant fraction of Milky Way (MW) satellites exhibit phase-space properties consistent with a coherent orbital plane. Using tailored N--body simulations of a spherical MW halo that recently captured a massive (1.8$\times 10^{11}$M$\odot$) LMC-like satellite, we identify the physical mechanisms that may enhance the clustering of orbital poles of objects orbiting the MW. The LMC deviates the orbital poles of MW dark matter (DM) particles from the present-day random distribution. Instead, the orbital poles of particles beyond $R\approx 50$kpc cluster near the present-day orbital pole of the LMC along a sinusoidal pattern across the sky. The density of orbital poles is enhanced near the LMC by a factor $\delta {\rho }_{max}$=30\%(50\%) with respect to underdense regions, and $\delta {\rho }_{iso}$=15\%(30\%) relative to the isolated MW simulation (no LMC) between 50-150 kpc (150-300 kpc). The clustering appears after the LMC's pericenter ($\approx$ 50 Myr ago, 49 kpc) and lasts for at least 1 Gyr. Clustering occurs because of three effects: 1) the LMC shifts the velocity and position of the central density of the MW's halo and disk; 2) the DM dynamical friction wake and collective response induced by the LMC changes the kinematics of particles; 3) observations of particles selected within spatial planes suffer from a bias, such that measuring orbital poles in a great circle in the sky enhances the probability of their orbital poles being clustered. This scenario should be ubiquitous in hosts that recently captured a massive satellite (at least $\approx$ 1:10 mass ratio), causing the clustering of orbital poles of halo tracers.

Submitted to ApJ. 23 pages and 16 figures. Comments are welcome

References in corpus (41)

• The NumPy array: a structure for efficient numerical computation
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• Tango for three: Sagittarius, LMC, and the Milky Way
• The M31 Velocity Vector. II. Radial Orbit Towards the Milky Way and Implied Local Group Mass
• Small Dwarf Galaxies Within Larger Dwarfs: Why Some Are Luminous While Most Go Dark
• The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions
• The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites
• Infall of substructures onto a Milky Way-like dark halo
• The M31 Velocity Vector. I. Hubble Space Telescope Proper Motion Measurements
• Orbits of Massive Satellite Galaxies: I. A Close Look at the Large Magellanic Cloud and a New Orbital History for M33
• Quantifying the impact of the Large Magellanic Cloud on the structure of the Milky Way's dark matter halo using Basis Function Expansions
• Measuring the Mass of the Large Magellanic Cloud with Stellar Streams Observed by $S^5$
• All-Sky Dynamical Response of the Galactic Halo to the Large Magellanic Cloud
• The Milky Way's Disk of Classical Satellite Galaxies in Light of Gaia DR2
• Detection of the Milky Way reflex motion due to the Large Magellanic Cloud infall
• Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. IV: Measurement for Sculptor
• Dynamics of the Magellanic Clouds in a LCDM Universe
• Detection of the LMC-induced sloshing of the Galactic halo
• Gaia EDR3 proper motions of Milky Way dwarfs I: 3D Motions and Orbits
• Fourteen candidate RR Lyrae star streams in the inner Galaxy
• Reflex motion in the Milky Way stellar halo resulting from the Large Magellanic Cloud infall
• Planes of satellites around Milky Way/M31-mass galaxies in the FIRE simulations and comparisons with the Local Group
• Equilibrium models of the Milky Way mass are biased high by the LMC
• The coherent motion of Cen A dwarf satellite galaxies remains a challenge for $\Lambda$CDM cosmology
• Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics
• Full 5D characterisation of the Sagittarius stream with Gaia DR2 RR Lyrae
• HST Proper Motions of NGC 147 and NGC 185: Orbital Histories and Test of Dynamically Coherent Andromeda Satellite Plane
• Radialization of satellite orbits in galaxy mergers
• Space Motions of the Dwarf Spheroidal Galaxies Draco and Sculptor based on HST Proper Motions with ~10-year Time Baseline
• Evolution of galactic planes of satellites in the EAGLE simulation
• The Vast Polar Structure of the Milky Way Attains New Members
• 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 Milky Way's stellar streams and globular clusters do not align in a Vast Polar Structure
• How Unusual is the Milky Way's Assembly History?
• Proper Motion of the Draco Dwarf Galaxy Based On Hubble Space Telescope Imaging
• The spatial distribution of Milky Way satellites, gaps in streams and the nature of dark matter
• Baryonic impact on the dark matter orbital properties of Milky Way-sized haloes
• Do halos that form early, have high concentration, are part of a pair, or contain a central galaxy potential host more pronounced planes of satellite galaxies?
• An updated detailed characterization of planes of satellites in the MW and M31
• Models of Distorted and Evolving Dark Matter Halos

Cited by in corpus (22)

• From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity
• Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies
• Measuring the Milky Way mass distribution in the presence of the LMC
• The effect of the LMC on the Milky Way system
• The SAGA Survey. III. A Census of 101 Satellite Systems around Milky Way-mass Galaxies
• Uncertainties associated with the backward integration of dwarf satellites using simple parametric potentials
• 3D hydrodynamic simulations for the formation of the Local Group satellite planes
• Discovery of the Magellanic Stellar Stream Out to 100 Kiloparsecs
• Mapping the anisotropic Galactic stellar halo with Blue Horizontal Branch stars
• Constraining the Milky Way halo kinematics via its Linear Response to the Large Magellanic Cloud
• Milky Way-est: Cosmological Zoom-in Simulations with Large Magellanic Cloud and Gaia-Sausage-Enceladus Analogs
• On the Effect of the Large Magellanic Cloud on the Orbital Poles of Milky Way Satellite Galaxies
• A portrait of the Vast Polar Structure as a young phenomenon: hints from its member satellites
• The satellite galaxy plane of NGC 4490 in light of ΛCDM - Sparsity of similarly extreme analogs and a possible role of satellite pairs
• The LMC impact on the kinematics of the Milky Way satellites: clues from the running solar apex
• Dynamical Data Mining Captures Disc-Halo Couplings that Structure Galaxies
• Satellite group infall into the Milky Way: exploring the Crater-Leo case with new HST proper motions
• The Magellanic Clouds are very rare in the IllustrisTNG simulations
• Planes of satellites around simulated disk galaxies II: Time-persistent planes of kinematically-coherent satellites in $\Lambda$CDM
• IFUM Integrated Field Spectroscopy of Ten M104 Satellite Galaxy Candidates
• An LBT view of the co-rotating group of galaxies around NGC 2750: Deep imaging and new satellite candidates
• The long-term stability of the Vast Polar Structure and its connection to a possible previous passage of the LMC