Young star forming regions are often associated with H2O masers, and occasionally with SiO masers, and radio VLBI can trace the spatial and kinematic distribution of the emission. In collaboration with Lincoln Greenhill, James Herrnstein, James Moran, and Karl Menten, I have mapped the H2O and SiO masers in the W51 high-mass star forming region, and find that the maser emission appears to trace an outflow from an obscured high-mass protostar (Eisner et al. 2002). We conducted a search for fainter H2O maser emission associated with young stars with the Green Bank Telescope, but found relatively few detections.
Water masers in the W51 star forming region. We mapped both water and silicon monoxide masers in this region, finding that they trace an outflow from an obscured, high-mass protostar.