The last Magellanic collision: The formation of the off-center bar, asymmetric HI spirals, and young stars in the Large Magellanic Cloud

We first present the results of fully self-consistent numerical simulations of the Large and Small Magellanic Clouds (LMC and SMC), which show that the last collision between the Magellanic clouds about ∼ 0.2 Gyr ago can form the apparently off-center bar and peculiar HI spirals of the LMC. We also show that the present spatial distributions of young stars with ages less than ∼ 20 Myr in the LMC can be significantly asymmetric and clumpy owing to dynamical and hydrodynamical interaction between the Clouds during the Magellanic collision. The simulated small but non-negligible fraction of stellar and gaseous components transferred from the SMC into the LMC are interpreted in terms of the observed diffuse HI gas surrounding the LMC and the globular cluster ESO 121-SC03 falling in the “age gap” between 3− 13 Gyr. Based on these results, we discuss the origin of Magellanic-type dwarfs with off-center bars in the context of their tidal interaction with their visible and invisible companions. Subject headings: galaxies: Magellanic Clouds — galaxies: star clusters — galaxies: stellar content – galaxies: interactions