2019/02/28 by Nicolas Garavito-Camargo, Gurtina Besla, Chervin F. P Laporte +3 · 1 citation
Physics and Astronomy · #astro-ph.GA #astro-ph.CO
paper · pdf · doi:10.3847/1538-4357/ab32eb
41 pages, 27 figures. Accepted to ApJ. Some terminology was changed. High-resolution images and figures can be found at https://bit.ly/2S25YzC
arxiv created 2019/09/11 · arxiv updated 2019/10/16
Satellite 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 (mdm = 4 × 104 M\odot ) 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 pronounced Local and Global wakes in both the DM and stellar halos, leads to both local overdensities and distinct kinematic patterns that should be observable with ongoing and future surveys. Specifically, the Global Wake will result in redshifted radial velocities of stars in the North and blueshifts in the South, at distances larger than 45 kpc. The Local Wake 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 and its orbital trajectory, the mass of the MW, and it may inform us about the nature of the dark matter particle itself.