The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites
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Garavito-Camargo_2021_ApJ_923_ ...
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Final Published Version
Author
Garavito-Camargo, N.Patel, E.
Besla, G.
Price-Whelan, A.M.
Gómez, F.A.
Laporte, C.F.P.
Johnston, K.V.
Affiliation
Steward Observatory, University of ArizonaIssue Date
2021
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IOP Publishing LtdCitation
Garavito-Camargo, N., Patel, E., Besla, G., Price-Whelan, A. M., Gómez, F. A., Laporte, C. F. P., & Johnston, K. V. (2021). The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites. Astrophysical Journal.Journal
Astrophysical JournalRights
Copyright © 2021. The American Astronomical Society. All rights reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.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 1011 M o˙) 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 particles from the present-day random distribution. Instead, the orbital poles of particles beyond R ≈ 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 δ ρmax = 30% (50%) with respect to underdense regions and δ ρ iso = 15% (30%) relative to the isolated MW simulation (no LMC) between 50 and 150 kpc (150-300 kpc). The clustering appears after the LMC's pericenter (≈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 dark matter dynamical friction wake and collective response induced by the LMC change 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 ≈1:10 mass ratio), causing the clustering of orbital poles of halo tracers. © 2021. The American Astronomical Society. All rights reserved.Note
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0004-637XVersion
Final published versionae974a485f413a2113503eed53cd6c53
10.3847/1538-4357/ac2c05