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The Large and Small Magellanic Clouds (LMC/SMC), as two of the closest and most massive satellites of the Milky Way, have significant effects on the local Universe; including on the orbits of tidal streams, and the distribution of ultra-faint satellites. However their masses, and interaction history beyond the most recent LMC/SMC close passage, remain poorly constrained. My thesis aims to understand the effects of past interactions between the Clouds by performing the first dedicated kinematic study of the Magellanic stellar outskirts. To do so, I have developed and led the Magellanic Edges Survey (MagES), a spectroscopic study using 2dF+AAOmega targeting ~8700 red clump and red giant branch stars across the highly-substructured periphery of the Clouds. In combination with astrometric measurements and high-precision photometry from the Gaia satellite, the survey provides 3D kinematics and abundance information critical for understanding the effects of dynamical perturbations on the Clouds. In this talk, I will present recent results from MagES on the kinematic and structural properties of the outer LMC, including the origin of a large arm-like substructure to the north of the LMC found to be predominantly formed during a recent interaction with the Milky Way; a sharp truncation in the western LMC disk likely due to an SMC crossing of the LMC disk plane ~400Myr ago; and complex southern substructures which are plausibly the result of multiple close interactions with the SMC over time. These are the first kinematic constraints on the dynamical history of the Clouds prior to their most recent close passage, and will be critical for guiding future numerical models aiming to accurately describe the complex evolution of the Magellanic system. |
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