WATER EMISSION AT 183 GHZ FROM HH7-11 AND OTHER LOW-MASS STAR-FORMINGREGIONS

The 3(13) --> 2(20) line of para water at 183.3 GHz (lambda = 1.67 mm) has been observed from the ground toward HH7-11 at three different da tes (in 1989, 1994 and 1995). The emission consists of several discret e spikes at velocities which are blueshifted with respect to the ambie nt cloud. The strongest spike appeared at a LSR velocity of -93 km s(- 1), much lower that the reported velocities of the previously known 22 GHz masers, and presents a significant spatial extent of >10 '' along the blueshifted lobe of the fast component of the CO outflow. The pro files are observed to be strongly time variable. We conclude that the water line emission at 183 GHz is of maser nature, and that it arises from a region which has been heated and shock-compressed by the action of the violent outflow emanating from SVS13. We also report the detec tion of strong water emission in L1448-mm. The spectrum consists of se veral velocity features and probably of a broad emission plateau. Fina lly, we report the results from a search for H2O 3(13) --> 2(20) emiss ion toward several dark clouds harboring HH objects and bipolar molecu lar outflows.