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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 the distribution of ultra-faint satellites, and the orbits of tidal streams. Ongoing survey efforts with the Dark Energy Camera have revealed a wealth of low-surface-brightness stellar substructures in the periphery of the Clouds; characterising these structures will provide significant insight into the currently poorly-constrained masses and interaction history of the Clouds. In order to elucidate the properties of the structures, we have used 2df+AAOmega at the Anglo Australian Telescope to instigate a large-scale spectroscopic follow-up of stars across the Magellanic periphery. We are able to detect the kinematic signature of the Clouds up to projected distances of 23 degrees from the centre of the LMC. Combining our spectroscopically derived radial velocities with Gaia DR2 astrometry provides the first 3D kinematics for these regions. Our initial set of measurements, along a large substructure to the north of the LMC, reveal radial velocities near the extremity of the substructure are significantly different from those expected from an extrapolation of the LMC rotation curve; this discrepancy may indicate a strong warp in the LMC disk. Our ultimate aim is to use these 3D kinematics to assess dynamical models of the Clouds; this will shed new light on the origin of the substructures, and the evolution of the Magellanic/Milky Way system. |
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