Magellanic satellites in $\Lambda$CDM cosmological hydrodynamical simulations of the Local Group

Abstract

We use the APOSTLE $\Lambda$CDM cosmological hydrodynamical simulations of the Local Group to study the recent accretion of massive satellites into the halo of Milky Way (MW)-sized galaxies. These systems are selected to be close analogues to the Large Magellanic Cloud (LMC), the most massive satellite of the MW. The simulations allow us to address, in a cosmological context, the impact of the Clouds on the MW, including the contribution of Magellanic satellites to the MW satellite population, and the constraints placed on the Galactic potential by the motion of the LMC. We show that LMC-like satellites are twice more common around Local Group-like primaries than around isolated halos of similar mass; these satellites come from large turnaround radii and are on highly eccentric orbits whose velocities at first pericentre are comparable with the primary's escape velocity. This implies $V_{\mathrm{esc}}^{\mathrm{MW}}(50$ kpc$)\sim 365$ km/s, a strong constraint on Galactic potential models. LMC analogues contribute about 2 satellites with $M_{\ast }>10^5{M}_{\odot }$, having thus only a mild impact on the luminous satellite population of their hosts. At first pericentre, LMC-associated satellites are close to the LMC in position and velocity, and are distributed along the LMC's orbital plane. Their orbital angular momenta roughly align with the LMC's, but, interestingly, they may appear to "counter-rotate" the MW in some cases. These criteria refine earlier estimates of the LMC association of MW satellites: only the SMC, Hydrus1, Car3, Hor1, Tuc4, Ret2 and Phoenix2 are compatible with all criteria. Carina, Grus2, Hor2 and Fornax are less probable associates given their large LMC relative velocity.

17 pages, 14 figures, 1 table. Accepted for publication in MNRAS

References in corpus (14)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• galpy: A Python Library for Galactic Dynamics
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• A chronicle of galaxy mass assembly in the EAGLE simulation
• The SAGA Survey. II. Building a Statistical Sample of Satellite Systems around Milky Way-like Galaxies
• Small Dwarf Galaxies Within Larger Dwarfs: Why Some Are Luminous While Most Go Dark
• Scaling Relations and the Fundamental Line of the Local Group Dwarf Galaxies
• Cosmic Ménage à Trois: The Origin of Satellite Galaxies On Extreme Orbits
• Orbits of Massive Satellite Galaxies: I. A Close Look at the Large Magellanic Cloud and a New Orbital History for M33
• Dynamics of the Magellanic Clouds in a LCDM Universe
• Revised and new proper motions for confirmed and candidate Milky Way dwarf galaxies
• The mass of the Milky Way out to 100 kpc using halo stars

Cited by in corpus (32)

• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• 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
• Extinguishing the FIRE: environmental quenching of satellite galaxies around Milky Way-mass hosts in simulations
• The SAGA Survey. III. A Census of 101 Satellite Systems around Milky Way-mass Galaxies
• The Most Metal-poor Stars in the Magellanic Clouds are $r$-process Enhanced
• The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites
• 3D hydrodynamic simulations for the formation of the Local Group satellite planes
• The effects of LMC-mass environments on their dwarf satellite galaxies in the FIRE simulations
• The spatial distribution of Milky Way satellites, gaps in streams and the nature of dark matter
• The impact of the Large Magellanic Cloud on dark matter direct detection signals
• A first estimate of the Milky Way dark matter halo spin
• Milky Way-est: Cosmological Zoom-in Simulations with Large Magellanic Cloud and Gaia-Sausage-Enceladus Analogs
• Satellite mass functions and the faint end of the galaxy mass-halo mass relation in LCDM
• The dark side of FIRE: predicting the population of dark matter subhaloes around Milky Way-mass galaxies
• Sizing from the Smallest Scales: The Mass of the Milky Way
• Vertical structure and kinematics of the LMC disc from SDSS/Gaia
• The tidal evolution of the Fornax dwarf spheroidal and its globular clusters
• Galactic satellite systems in CDM, WDM and SIDM
• The Tucana dwarf spheroidal: a distant backsplash galaxy of M31?
• Auriga Streams I: disrupting satellites surrounding Milky Way-mass haloes at multiple resolutions
• The Magellanic Clouds are very rare in the IllustrisTNG simulations
• No globular cluster progenitors in Milky Way satellite galaxies
• Can tides explain the low dark matter density in Fornax?
• Following the tidal trail: a history of modeling the Magellanic Stream
• The effect of environment on the mass assembly history of the Milky Way and M31
• Are there any extragalactic high speed dark matter particles in the Solar neighborhood?
• Auriga Streams II: orbital properties of tidally disrupting satellites of Milky Way-mass galaxies
• DELVE Milky Way Satellite Galaxy Census I: Satellite Population and Survey Selection Function in DES, DELVE, and Pan-STARRS
• Magellanic System Stars Identified in SMACS J0723.3-7327 James Webb Space Telescope Early Release Observations Images
• Broken Expectations: The Effects of Modelling Assumptions on the Inferred Dark Matter Distribution in the Milky Way's Satellites
• The long-term stability of the Vast Polar Structure and its connection to a possible previous passage of the LMC