Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud
Laporte, Chervin F. P.
Johnston, Kathryn V.
Gómez, Facundo A.
Watkins, Laura L.
AffiliationUniv Arizona, Steward Observ
KeywordsGalaxy: kinematics and dynamics
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationNicolas Garavito-Camargo et al 2019 ApJ 884 51
RightsCopyright © 2019. The American Astronomical Society. All rights reserved.
Collection InformationThis 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 firstname.lastname@example.org.
AbstractSatellite galaxies are predicted to generate gravitational density wakes as they orbit within the dark matter (DM) halos of their hosts, causing their orbits to decay over time. The recent infall of the Milky Way's (MW) most massive satellite galaxy, the Large Magellanic Cloud (LMC), affords us the unique opportunity to study this process in action. In this work, we present high-resolution (m(dm) = 4 x 10(4) M-circle dot) N-body simulations of the MW-LMC interaction over the past 2 Gyr. We quantify the impact of the LMC's passage on the density and kinematics of the MW's DM halo and the observability of these structures in the MW's stellar halo. The LMC is found to generate a pronounced wake, which we decompose in Transient and Collective responses, in both the DM and stellar halos. The wake leads to overdensities and distinct kinematic patterns that should be observable with ongoing and future surveys. Specifically, the Collective response will result in redshifted radial velocities of stars in the north and blueshifts in the south, at distances >45 kpc. The Transient response traces the orbital path of the LMC through the halo (50-200 kpc), resulting in a stellar overdensity with a distinct, tangential kinematic pattern that persists to the present day. The detection of the MW's halo response will constrain the infall mass of the LMC, its orbital trajectory, and the mass of the MW, and it may inform us about the nature of the DM particle itself.
VersionFinal published version
SponsorsHST grant [AR 15004]; NASA ATP grant [17-ATP17-0006]; Vatican Observatory Stoeger-McCarthy fellowship; National Science FoundationNational Science Foundation (NSF) ; Writing Skills Improvement Program from the University of Arizona; NSFNational Science Foundation (NSF) [AST-1715582]; CONICYT through the project FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT ; Max Planck Society through a Partner Group grant; European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programmeEuropean Research Council (ERC)