Shocks and outflows in regions of star formation

Protostellar outflows are widely associated with regions of active star formation. Such outflows drive shocks into the surrounding material, with an environmental impact that may affect the course of future star formation. Interstellar shocks heat and compress the surrounding gas, modifying its chemical composition, and can vaporize material both in grain mantles and grain cores. Recent results from the Infrared Space Observatory and the Submillimeter Wave Astronomy Satellite demonstrate that the abundance of water vapor is greatly enhanced within warm shock-heated gas, confirming a long-standing theoretical prediction. Future observations obtained with millimeter and submillimeter interferometers such as ALMA promise to furthur elucidate the physical and chemical conditions in outflows and shocks by allowing multitransition spectral line studies to be carried out at unprecedented angular resolution.