Supersonic Water Masers in 30 Doradus

We report on extremely high velocity molecular gas, up to −80 km s relative to the ambient medium, in the giant star-formation complex 30 Doradus in the Large Magellanic Cloud (LMC), as observed in new 22 GHz H2O 616 → 523 maser emission spectra obtained with the Mopra radio telescope. The masers may trace the velocities of protostars, and the observed morphology and kinematics indicate that current star formation occurs near the interfaces of colliding stellar-wind blown bubbles. The large space velocities of the protostars and associated gas could result in efficient mixing of the LMC. A similar mechanism in the Milky Way could seed the galactic halo with relatively young stars and gas. Subject headings: Masers – Stars: formation – ISM: bubbles – ISM: individual objects: 30 Dor – ISM: kinematics and dynamics – Magellanic Clouds.