An Interaction of a Magellanic Leading Arm High Velocity Cloud with the Milky Way Disk

Abstract

The Leading Arm of the Magellanic System is a tidally formed HI feature extending $\sim 60\arcdeg$ from the Magellanic Clouds ahead of their direction of motion. Using atomic hydrogen (HI) data from the Galactic All Sky-Survey (GASS), supplemented with data from the Australia Telescope Compact Array, we have found evidence for an interaction between a cloud in the Leading Arm and the Galactic disk where the Leading Arm crosses the Galactic plane. The interaction occurs at velocities permitted by Galactic rotation, which allows us to derive a kinematic distance to the cloud of 21 kpc, suggesting that the Leading Arm crosses the Galactic Plane at a Galactic radius of $R\approx 17$ kpc.

14 pages, 5 figures, accepted to Astrophysical Journal Letters. Full resolution version available at ftp://ftp.atnf.csiro.au/pub/people/nmcclure/papers/LeadingArm_apjl.pdf

References in corpus (4)

• Are the Magellanic Clouds on their First Passage about the Milky Way?
• Is the SMC Bound to the LMC? The HST Proper Motion of the SMC
• The Spiral Structure of the Outer Milky Way in Hydrogen
• The dynamics of tidal tails from massive satellites

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