OH masers and bipolar molecular outflows associated with massive star formation

Abstract

I present observations of the OH maser emission from G5.89-0.39 (W28A2), the most massive bipolar molecular outflow in the Galaxy. ^Together with recombination line and molecular line observations, these data suggest that a massive star is embedded in a dense disk of molecular gas. ^The star ionizes the inside of the disk and powers the bipolar outflow. ^OH masers form in the shocked regions just outside the ultracompact H II region. ^G5.89-0.39 represents an important link between the phenomena of low and high mass star formation as well as a chance to study the engine of a bipolar outflow in great detail.