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arXiv · 2305.02755

Star Formation History of the Small Magellanic Cloud: the shell substructure

Joanna D. Sakowska·Noelia E. D. Noël·Tomás Ruiz-Lara·Carme Gallart
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Abstract

We present the spatially resolved star formation history (SFH) of a shell-like structure located in the northeastern Small Magellanic Cloud (SMC). We quantitatively obtain the SFH using unprecedented deep photometric data (g~24 magnitude) from the SMASH survey and colour-magnitude diagram (CMD) fitting techniques. We consider, for the first time, the SMC's line-of-sight depth and its optical effects on the CMDs. The SFH presents higher accuracy when a line-of-sight depth of ~3 Kpc is simulated. We find young star formation enhancements at ~150 Myr, ~200 Myr, ~450 Myr, ~650 Myr, and ~1 Gyr. Comparing the shell's SFH with the Large Magellanic Cloud's (LMC) northern arm SFH we show strong evidence of synchronicity from at least the past ~2.8 Gyr and, possibly, the past ~3.5 Gyr. Our results place constraints on the orbital history of the Magellanic Clouds which, potentially, have implications on their dynamical mass estimates.

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Joanna D. Sakowska, Noelia E. D. Noël, Tomás Ruiz-Lara, Carme Gallart. 2023-05-04. Star Formation History of the Small Magellanic Cloud: the shell substructure. https://arxiv.org/abs/2305.02755

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