Response of the Milky Way's disc to the Large Magellanic Cloud in a first infall scenario

Chervin F.P. Laporte, Facundo A. Gómez, Gurtina Besla, Kathryn V. Johnston, Nicolas Garavito-Camargo

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

We present N-body and hydrodynamical simulations of the response of the Milky Way's baryonic disc to the presence of the Large Magellanic Cloud during a first infall scenario. For a fiducial Galactic model reproducing the gross properties of the Galaxy, we explore a set of six initial conditions for the Large Magellanic Cloud (LMC) of varying mass which all evolve to fit the measured constraints on its current position and velocity with respect to the Galactic Centre. We find that the LMC can produce strong disturbances - warping of the stellar and gaseous discs - in the Galaxy, without violating constraints from the phasespace distribution of stars in the Solar Neighbourhood. All models correctly reproduce the phases of the warp and its antisymmetrical shape about the disc's mid-plane. If the warp is due to the LMC alone, then the largest mass model is favoured (2.5 × 1011 M). Still, some quantitative discrepancies remain, including deficits in height of ΔZ = 0.7 kpc at R = 22 kpc and ΔZ = 0.7 kpc at R = 16 kpc. This suggests that even higher infall masses for the LMC's halo are allowed by the data. A comparison with the vertical perturbations induced by a heavy Sagittarius dSph model (1011 M) suggest that positive interference with the LMC warp is expected at R = 16 kpc. We conclude that the vertical structure of the Galactic disc beyond the Solar Neighbourhood may jointly be shaped by its most massive satellites. As such, the current structure of the Milky Way suggests we are seeing the process of disc heating by satellite interactions in action.

Original languageEnglish (US)
Pages (from-to)1218-1230
Number of pages13
JournalMonthly Notices of the Royal Astronomical Society
Volume473
Issue number1
DOIs
StatePublished - Jan 1 2018

Keywords

  • Galaxy: disc
  • Galaxy: evolution
  • Galaxy: kinematics and dynamics
  • Galaxy: structure

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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