Evolution of the Small Magellanic Cloud

TL;DR

This study uses N-body simulations to explore the Magellanic Clouds' interaction with the Galaxy over 2.5 billion years, revealing the formation of structures, gas transfer, and implications for star formation in the LMC.

Contribution

It provides new insights into the timing and locations of Magellanic stream features, gas transfer processes, and their impact on star formation in the LMC based on detailed simulations.

Findings

Leading arms pass through the Galactic plane after MS formation.

Collisions create HI holes and chimney structures in the Galactic disk.

Metal-poor gas from SMC contributes to low-metallicity stars in LMC.

Abstract

Based on the results of N-body simulations on the last 2.5 Gyr evolution of the Large and Small Magellanic Clouds (LMC and SMC, respectively) interacting with the Galaxy, we firstly show when and where the leading arms (LAs) of the Magellanic stream (MS) can pass through the Galactic plane after the MS formation. We secondly show collisions between the outer Galactic HI disk and the LAs of the MS can create giant HI holes and chimney-like structures in the disk about 0.2 Gyr ago. We thirdly show that a large amount of metal-poor gas is stripped from the SMC and transfered to the LMC during the tidal interaction between the Clouds and the Galaxy about 0.2 and 1.3 Gyr ago. We thus propose that this metal-poor gas can closely be associated with the origin of LMC's young and intermediate-age stars and star clusters with distinctively low-metallicities with [Fe/H] < -0.6.