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Explaining the mysterious age gap of globular clusters in the Large Magellanic Cloud

K. Bekki·W. J. Couch·M. A. Beasley·D. A. Forbes·M. Chiba·G. S. Da Costa
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Abstract

The Large Magellanic Cloud (LMC) has a unique cluster formation history in that nearly all of its globular clusters were formed either $\sim$ 13 Gyr ago or less than $\sim$ 3 Gyr ago. It is not clear what physical mechanism is responsible for the most recent cluster formation episode and thus the mysterious age gap between the LMC clusters. We first present results of gas dynamical N-body simulations of the evolution of the LMC in the context of its Galactic orbit and interactions with the SMC, paying special attention to the effect of tidal forces. We find that the first close encounter between the LMC and the Small Magellanic Cloud (SMC) about 4 Gyr ago was the beginning of a period of strong tidal interaction which likely induced dramatic gas cloud collisions, leading to an enhancement of the formation of globular clusters which has been sustained by strong tidal interactions to the present day. The tidal interaction results in the formation of a barred, elliptical, thick disk in the LMC. The model also predicts the presence of a large, diffuse stellar stream circling the Galaxy, which originated from the LMC.

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K. Bekki, W. J. Couch, M. A. Beasley, D. A. Forbes, M. Chiba, G. S. Da Costa. 2004-06-20. Explaining the mysterious age gap of globular clusters in the Large Magellanic Cloud. https://doi.org/10.1086/423372

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