Absolute proper motions of H2O masers away from the galactic plane measured with VERA in the Superbubble region NGC 281

We report on absolute proper-motion measurements of an H2O maser source in the NGC 281 West molecular cloud, which is located similar to 320 pc above. the Galactic plane and is associated with an Hi loop extending from the Galactic plane. We conducted multi-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) over a monitoring period of 6 months, since 2006 May. We find that the H2O maser features in NGC 281 West are systematically moving toward the southwest and further away from the Galactic plane with a vertical velocity of 20-30 km s(-1) at its estimated distance of 2.2-3.5 kpc. Our new results provide the most direct evidence that the gas in the NGC 281 region on the H I loop was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.