Water masers in the direction of the galactic center. 1: Results from initial observations

Abstract

We present preliminary results from a search for water masers in the inner 4 deg x 4 deg of the Galaxy using the Very Large Array (VLA). Of 97 IRAS-selected sources observed, we report the detection of 30 H2O masers (31%). Five of these sources had previously been detected as H2O masers, six are known OH/IR stars, and one is a known SiO maser. On the basis of their infrared colors, and their H2O spectra, we categorize 14 sources as in star forming regions, 13 sources as circumstellar masers, and 3 as unknown. Seven H2O masers have been found with LSR velocities exceeding 30 km/s, indicating that they are located in the Galactic Center region. The fact remains that relatively few H2O masers have been found in the inner few hundred parsecs of the Galaxy in spite of the large concentration of molecular gas in this region.