High-resolution observations of water masers in Bok globules

Abstract

We present Very Large Array observations at 1.3 cm of several water maser detections obtained by previous single-dish studies of Bok globules in the Clemens & Barvainis (1988; CB) catalog. We report water maser emission in CB 3 (CB3-mm), CB 54 (IRAS 07020-1618), CB 101 (IRAS 17503-0833), and CB 232 (IRAS 21352+4307), and non-detection towards CB 65 (IRAS 16277-2332) and CB 205 (IRAS 19433+2743). These are the first reported interferometric observations of water masers in Bok globules of the CB catalog. We also present single-dish observations of millimeter and centimeter spectral lines towards CB 101 (IRAS 17503-0833) and CB 65 (IRAS 16277-2332). All the maser emission seems to be associated with star forming regions hosting bipolar molecular outflows, except IRAS 17503-0833 in CB 101, which we suggest to be a possible Mira evolved star, and IRAS 16277-2332 in CB 65, of unknown nature. We have used the precise position of the maser emission to derive information about the powering source of the masers. By analyzing the spatio-kinematical distribution of the water masers, we confirm the millimeter source CB 3-mm as the most likely powering source of the CB 3 masers. We propose the near-IR source CB 232 YC1-I as the best candidate for pumping the maser emission observed in CB 232, while in CB 54, we suggest that the pumping source of the masers could be located at the position of an elongated feature observed in near-infrared maps.