The Magellanic Inter-Cloud Project (MAGIC) III: First spectroscopic evidence of a dwarf stripping a dwarf

Abstract

The Magellanic Bridge (MB) is a gaseous stream that links the Large (LMC) and Small (SMC) Magellanic Clouds. Current simulations suggest that the MB forms from a recent interaction between the Clouds. In this scenario, the MB should also have an associated stellar bridge formed by stars tidally stripped from the SMC by the LMC. There are several observational evidences for these stripped stars, from the presence of intermediate age populations in the MB and carbon stars, to the recent observation of an over-density of RR Lyrae stars offset from the MB. However, spectroscopic confirmation of stripped stars in the MB remains lacking. In this paper, we use medium resolution spectra to derive the radial velocities and metallicities of stars in two fields along the MB. We show from both their chemistry and kinematics that the bulk of these stars must have been tidally stripped from the SMC. This is the first spectroscopic evidence for a dwarf galaxy being tidally stripped by a larger dwarf.

Accepted for publication in MNRAS: 8 pages, 6 figures

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Cited by in corpus (15)

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• A SkyMapper view of the Large Magellanic Cloud: The dynamics of stellar populations
• The VMC survey -- XLI. Stellar proper motions within the Small Magellanic Cloud
• Magellanic Mayhem: Metallicities and Motions
• Stellar substructures in the periphery of the Magellanic Clouds with the VISTA Hemisphere Survey from the red clump and other tracers
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• Presence of red giant population in the foreground stellar sub-structure of the Small Magellanic Cloud
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• Discovery of NES, an extended tidal structure in the North-East of the Large Magellanic Cloud
• Asymmetries in the LMC velocity maps
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• Strömgren photometric metallicity map of the Magellanic Cloud stars using Gaia DR3--XP spectra
• Revisiting the near infrared Calcium triplet as metallicity indicator