On the origin of the asymmetric dwarf galaxy distribution around Andromeda

Abstract

The dwarf galaxy distribution surrounding M31 is significantly anisotropic in nature. Of the 30 dwarf galaxies in this distribution, 15 form a disc-like structure and 23 are contained within the hemisphere facing the Milky Way. Using a realistic local potential, we analyse the conditions required to produce and maintain these asymmetries. We find that some dwarf galaxies are required to have highly eccentric orbits in order to preserve the presence of the hemispherical asymmetry with an appropriately large radial dispersion. Under the assumption that the dwarf galaxies originate from a single association or accretion event, we find that the initial size and specific energy of that association must both be relatively large in order to produce the observed hemispherical asymmetry. However if the association was large in physical size, the very high-energy required would enable several dwarf galaxies to escape from the M31 and be captured by the Milky Way. Furthermore, we find that associations that result in this structure have total specific energies concentrated around $E=V_{esc}^2-V_{init}^2\sim 200^2$ -- $300^2\mathrm{k}{\mathrm{m}}^2{\mathrm{s}}^{-2}$, implying that the initial velocity and initial position needed to produce the structure are strongly correlated. The overlap of initial conditions required to produce the radial dispersion, angular dispersion, and the planar structure is small and suggests that either they did not originate from a single accretion event, or that these asymmetric structures are short-lived.

arXiv comment12 pages, 10 figures, accepted by MNRAS

References in corpus (72)

• The Structure of Cold Dark Matter Halos
• Local Kinematics and the Local Standard of Rest
• The observed properties of dwarf galaxies in and around the Local Group
• galpy: A Python Library for Galactic Dynamics
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• The remnants of galaxy formation from a panoramic survey of the region around M31
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• A direct dynamical measurement of the Milky Way's disk surface density profile, disk scale length, and dark matter profile at 4 kpc < R < 9 kpc
• The Local Dark Matter Density
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• The great disk of Milky-Way satellites and cosmological sub-structures
• The Masses of the Milky Way and Andromeda galaxies
• The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way
• The local density of matter mapped by Hipparcos
• The Anisotropic Distribution of Galactic Satellites
• Thin, thick and dark discs in LCDM
• The Effect of Dissipation on the Shapes of Dark halos
• Masses for the Local Group and the Milky Way
• Mass and shape of the Milky Way's dark matter halo with globular clusters from Gaia and Hubble
• A timing constraint on the (total) mass of the Large Magellanic Cloud
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• The spatial distribution of the Milky Way and Andromeda satellite galaxies
• The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks Versus Substructures
• Small Dwarf Galaxies Within Larger Dwarfs: Why Some Are Luminous While Most Go Dark
• Kinematics of the stellar halo and the mass distribution of the Milky Way using BHB stars
• PAndAS' progeny: extending the M31 dwarf galaxy cabal
• A Bayesian Approach to Locating the Red Giant Branch Tip Magnitude (Part II); Distances to the Satellites of M31
• The rotationally stabilized VPOS and predicted proper motions of the Milky Way satellite galaxies
• 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 Three-Dimensional Structure of the M31 Satellite System; Strong Evidence for an Inhomogeneous Distribution of Satellites
• The Gravitational Potential Near the Sun From SEGUE K-dwarf Kinematics
• Gaia Proper Motions and Orbits of the Ultra-Faint Milky Way Satellites
• The cold veil of the Milky Way stellar halo
• The preferred direction of infalling satellite galaxies in the Local Group
• Planes of satellite galaxies and the cosmic web
• Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant
• The satellite distribution of M31
• A thousand shadows of Andromeda: rotating planes of satellites in the Millennium-II cosmological simulation
• First Gaia Dynamics of the Andromeda System: DR2 Proper Motions, Orbits, and Rotation of M31 and M33
• The Gravitational Force Field of the Galaxy Measured From the Kinematics of RR Lyrae in Gaia
• Planes of satellite galaxies: when exceptions are the rule
• The Link between Galactic Satellite Orbits and Subhalo Accretion
• Absolute HST Proper Motion (HSTPROMO) of Distant Milky Way Globular Clusters: Galactocentric Space Velocities and the Milky Way Mass
• Determining orbits for the Milky Way's dwarfs
• The Spatial Distribution of Galactic Satellites in the LCDM Cosmology
• A Revised LCDM Mass Model For The Andromeda Galaxy
• Alignments between galaxies, satellite systems and haloes
• Strangers in the night: Discovery of a dwarf spheroidal galaxy on its first Local Group infall
• Vast planes of satellites in a high resolution simulation of the Local Group: comparison to Andromeda
• A new spin on disks of satellite galaxies
• A comparison of the distribution of satellite galaxies around Andromeda and the results of $\Lambda$CDM simulations
• Are rotating planes of satellite galaxies ubiquitous?
• Simulated ΛCDM analogues of the thin Plane of Satellites around the Andromeda galaxy are not kinematically coherent structures
• The lopsided distribution of satellite galaxies
• Evidence for Early Filamentary Accretion from the Andromeda Galaxy's Thin Plane of Satellites
• Dwarfs walking in a row. The filamentary nature of the NGC3109 association
• Triaxial Cosmological Haloes and the Disc of Satellites
• 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?
• The Origin of Lopsided Satellite Galaxy Distribution in Galaxy Pairs
• We are not the 99 percent: quantifying asphericity in the distribution of Local Group satellites
• The prolate dark matter halo of the Andromeda galaxy
• Is there a disk of satellites around the Milky Way?
• On Asymmetric Distributions of Satellite Galaxies
• The shape alignment of satellite galaxies in galaxy pairs in SDSS
• The co-planarity of satellite galaxies delivered by randomly aligned cold mode accretion streams
• Tidal Effects on the Spatial Structure of the Local Group
• A Dwarf Disrupting -- Andromeda XXVII and the North West Stream
• Proper Motions of the Satellites of M31
• Determining orbits for the Milky Way's dwarfs
• Group infall of substructures on to a Milky Way-like dark halo

Cited by in corpus (4)

• The Hubble Space Telescope Survey of M31 Satellite Galaxies I. RR Lyrae-based Distances and Refined 3D Geometric Structure
• The PAndAS View of the Andromeda Satellite System. IV Global properties
• The lopsided distribution of satellites of isolated central galaxies
• Andromeda's asymmetric satellite system as a challenge to cold dark matter cosmology