The LMC impact on the kinematics of the Milky Way satellites: clues from the running solar apex

Abstract

Dwarf galaxies provide a unique opportunity for studying the evolution of the Milky Way (MW) and the Local Group as a whole. Analysing the running solar apex based on the kinematics of the MW satellites, we discovered an unexpected behaviour of the dipole term of the radial velocity distribution as a function of the galactocentric distance. The nearby satellites (<100 kpc) have a bulk motion with an amplitude of 140-230 km/s while the more distant ones show an isotropic distribution of the radial velocities. Such strong solar apex variations can not be explained by the net rotation of the satellites, as it would require an enormously high rotation rate (~970 km/s). If we exclude the LMC and its most closely related members from our sample, this does not suppress the bulk motion of the nearby satellites strongly enough. Nevertheless, we have demonstrated that the observed peculiar kinematics of the MW satellites can be explained by a perturbation caused by the first infall of the LMC. First, we `undone' the effect of the perturbation by integrating the orbits of the MW satellites backwards (forwards) with (without) massive LMC. It appears that the present-day peculiar enhancement of the solar apex in the inner halo is diminished the most in the case of 2x10^{11} Msun LMC. Next, in self-consistent high-resolution N-body simulations of the MW-LMC interaction, we found that the solar apex shows the observed behaviour only for the halo particles with substantial angular momentum, comparable to that of the MW satellites.

13 pages, 9 figures, accepted for publication in MNRAS

References in corpus (35)

• The mass distribution and gravitational potential of the Milky Way
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• Tango for three: Sagittarius, LMC, and the Milky Way
• Is the SMC Bound to the LMC? The HST Proper Motion of the SMC
• The spatial distribution of the Milky Way and Andromeda satellite galaxies
• Milky Way Satellite Census. I. The Observational Selection Function for Milky Way Satellites in DES Y3 and Pan-STARRS DR1
• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• Two Planes of Satellites in the Centaurus A Group
• Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies
• All-Sky Dynamical Response of the Galactic Halo to the Large Magellanic Cloud
• Detection of the Milky Way reflex motion due to the Large Magellanic Cloud infall
• Cosmicflows-3: Two Distance$-$Velocity Calculators
• Detection of the LMC-induced sloshing of the Galactic halo
• Revised and new proper motions for confirmed and candidate Milky Way dwarf galaxies
• Kinematics of Antlia 2 and Crater 2 from The Southern Stellar Stream Spectroscopic Survey (S5)
• Two Ultra-Faint Milky Way Stellar Systems Discovered in Early Data from the DECam Local Volume Exploration Survey
• Reflex motion in the Milky Way stellar halo resulting from the Large Magellanic Cloud infall
• Equilibrium models of the Milky Way mass are biased high by the LMC
• The Pisces Plume and the Magellanic Wake
• The Edge of the Galaxy
• Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics
• Tracing satellite planes in the Sculptor group: I. Discovery of three faint dwarf galaxies around NGC 253
• VLT Spectroscopy of Ultra-Faint Dwarf Galaxies. 1. Boötes I, Leo IV, Leo V
• Chemo-kinematics of the Milky Way spiral arms and bar resonances: connection to ridges and moving groups in the Solar vicinity
• The chemical signature of the Galactic spiral arms revealed by Gaia DR3
• The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites
• The Pristine Dwarf-Galaxy survey -- III. Revealing the nature of the Milky Way globular cluster Sagittarius II
• Revisiting dynamical friction: the role of global modes and local wakes
• Numerical code for multi-component galaxies: from N-body to chemistry and magnetic fields
• A Deeper Look at DES Dwarf Galaxy Candidates: Grus I and Indus II
• The Effects of Dwarf Galaxies on the Orbital Evolution of Galactic Globular Clusters
• Cosmic flow around local massive galaxies
• On the Effect of the Large Magellanic Cloud on the Orbital Poles of Milky Way Satellite Galaxies
• Uncovering the Orbit of the Hercules Dwarf Galaxy

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