Simulated ΛCDM analogues of the thin Plane of Satellites around the Andromeda galaxy are not kinematically coherent structures

Abstract

A large fraction of the dwarf satellites orbiting the Andromeda galaxy are surprisingly aligned in a thin, extended and apparently kinematically coherent planar structure. Such a structure is not easily found in simulations based on the Cold Dark Matter model (ΛCDM). Using 21 high resolution cosmological simulations we analyse the kinematics of planes of satellites similar to the one around Andromeda. We find good agreement when co-rotation is characterized by the line-of-sight velocity. At the same time, when co-rotation is inferred by the angular momenta of the satellites, the planes are in agreement with the plane around our Galaxy. We find such planes to be common in our high concentration haloes. The number of co-rotating satellites obtained from the sign of the line-of-sight velocity shows large variations depending on the viewing angle and is consistent with that obtained from a sample with random velocities. We find that the clustering of angular momentum vectors of the satellites in the plane is a better measure of the kinematic coherence. Thus we conclude that the line-of- sight velocity is not well suited as a proxy for the kinematical coherence of the plane. Analysis of the kinematics of our planes shows a fraction of $\sim$30% chance aligned satellites. Tracking the satellites in the plane back in time reveals that these planes are a transient feature and not kinematically coherent as would appear at first sight. Thus we expect some of the satellites in the plane around Andromeda to have high velocities perpendicular to the plane.

19 pages, 15 figures, MNRAS accepted, Analysis strongly improved, paper shortened but main conclusions unchanged

References in corpus (24)

• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Astrophysics Source Code Library
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations
• NIHAO IV: Core creation and destruction in dark matter density profiles across cosmic time
• 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
• Two Planes of Satellites in the Centaurus A Group
• The M31 Velocity Vector. I. Hubble Space Telescope Proper Motion Measurements
• A dynamical model of the local cosmic expansion
• A thousand shadows of Andromeda: rotating planes of satellites in the Millennium-II cosmological simulation
• Planes of satellite galaxies: when exceptions are the rule
• The universal nature of subhalo accretion
• Luminosity and stellar mass functions of disks and spheroids in the SDSS and the supermassive black hole mass function
• The new Milky Way satellites: alignment with the VPOS and predictions for proper motions and velocity dispersions
• NIHAO V: Too big doesn't fail -- reconciling the conflict between LCDM predictions and the circular velocities of nearby field galaxies
• Vast planes of satellites in a high resolution simulation of the Local Group: comparison to Andromeda
• Spectroscopy of the three distant Andromedan satellites Cassiopeia III, Lacerta I, and Perseus I
• Are rotating planes of satellite galaxies ubiquitous?
• The Vast Polar Structure of the Milky Way Attains New Members
• Evidence for Early Filamentary Accretion from the Andromeda Galaxy's Thin Plane of Satellites
• Eppur si muove: Positional and kinematic correlations of satellite pairs in the low Z universe
• A Formation Scenario for the Disk of Satellites: Accretion of Satellites during Mergers

Cited by in corpus (31)

• Small-Scale Challenges to the $\Lambda$CDM Paradigm
• A whirling plane of satellite galaxies around Centaurus A challenges cold dark matter cosmology
• The large-scale structure of the halo of the Andromeda galaxy II. Hierarchical structure in the Pan-Andromeda Archaeological Survey
• NIHAO XV: The environmental impact of the host galaxy on galactic satellite and field dwarf galaxies
• Planes of satellites around Milky Way/M31-mass galaxies in the FIRE simulations and comparisons with the Local Group
• The coherent motion of Cen A dwarf satellite galaxies remains a challenge for $\Lambda$CDM cosmology
• Alignments between galaxies, satellite systems and haloes
• The edge of galaxy formation I: formation and evolution of MW-satellites analogues before accretion
• Stellar Masses of Giant Clumps in CANDELS and Simulated Galaxies Using Machine Learning
• Evolution of galactic planes of satellites in the EAGLE simulation
• The Role of Baryons in Creating Statistically Significant Planes of Satellites around Milky Way-Mass Galaxies
• With and without spectroscopy: Gaia DR2 proper motions of seven Ultra-Faint Dwarf Galaxies
• The twisted dark matter halo of the Milky Way
• On the Co-Orbitation of Satellite Galaxies Along the Great Plane of Andromeda: NGC 147, NGC 185, and Expectations from Cosmological Simulations
• 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
• Planes of satellites around simulated disc galaxies: I.- Finding high-quality planar configurations from positional information and their comparison to MW/M31 data
• Sizing from the Smallest Scales: The Mass of the Milky Way
• We are not the 99 percent: quantifying asphericity in the distribution of Local Group satellites
• Is there a disk of satellites around the Milky Way?
• The imprint of galaxy mergers on satellite planes in a cosmological context
• Is the vast polar structure of dwarf galaxies a serious problem for lambda cold dark matter?
• New dwarf galaxy candidates in the sphere of influence of the Sombrero galaxy
• A deeper look into the structure of ΛCDM haloes: correlations between halo parameters from Einasto fits
• Planes of satellites around simulated disk galaxies II: Time-persistent planes of kinematically-coherent satellites in $\Lambda$CDM
• Addressing via N-body simulations the distribution of the satellite tidal debris in the Milky Way environment
• On the origin of the asymmetric dwarf galaxy distribution around Andromeda
• Proper Motions of the Satellites of M31
• Sardinia Radio Telescope observations of Local Group dwarf galaxies -- I. The cases of NGC6822, IC1613, and WLM
• Dwarf Galaxies in the MATLAS Survey: The satellite system of NGC474 under scrutiny with MUSE
• IFUM Integrated Field Spectroscopy of Ten M104 Satellite Galaxy Candidates