Models of Tidally Induced Gas Filaments in the Magellanic Stream
  The Magellanic Stream and Leading Arm of HI that stretches from the Large and
Small Magellanic Clouds (LMC and SMC) and over 200 degrees of the Southern sky
is thought to be formed from multiple encounters between the LMC and SMC. In
this scenario, most of the gas in the Stream and Leading Arm is stripped from
the SMC, yet recent observations have shown a bifurcation of the Trailing Arm
that reveals LMC origins for some of the gas. Absorption measurements in the
Stream also reveal an order of magnitude more gas than in current tidal models.
We present hydrodynamical simulations of the multiple encounters between the
LMC and SMC at their first pass around the Milky Way, assuming that the Clouds
were more extended and gas rich in the past. Our models create filamentary
structures of gas in the Trailing Stream from both the LMC and SMC. While the
SMC trailing filament matches the observed Stream location, the LMC filament is
offset. In addition, the total observed mass of the Stream in these models is
underestimated of a factor of four when the ionized component is accounted for.
Our results suggest that there should also be gas stripped from both the LMC
and SMC in the Leading Arm, mirroring the bifurcation in the Trailing Stream.
This prediction is consistent with recent measurements of spatial variation in
chemical abundances in the Leading Arm, which show that gas from multiple
sources is present, although the nature is still uncertain.
