We observed CO J = 3 - 2 emission from the “ water fountain ” sources , which exhibit high-velocity collimated stellar jets traced by H _ { 2 } O maser emission , with the Atacama Submillimeter Telescope Experiment ( ASTE ) 10 m telescope .
We detected the CO emission from two sources , IRAS 16342 - 3814 and IRAS 18286 - 0959 .
The IRAS 16342 - 3814 CO emission exhibits a spectrum that is well fit to a Gaussian profile , rather than to a parabolic profile , with a velocity width ( FWHM ) of 158 \pm 6 km s ^ { -1 } and an intensity peak at V _ { \mbox { \scriptsize LSR } } = 50 \pm 2 km s ^ { -1 } .
The mass loss rate of the star is estimated to be \sim 2.9 \times 10 ^ { -5 } M _ { \odot } yr ^ { -1 } .
Our morpho-kinematic models suggest that the CO emission is optically thin and associated with a bipolar outflow rather than with a ( cold and relatively small ) torus .
The IRAS 18286 - 0959 CO emission has a velocity width ( FWHM ) of 3.0 \pm 0.2 km s ^ { -1 } , smaller than typically seen in AGB envelopes .
The narrow velocity width of the CO emission suggests that it originates from either an interstellar molecular cloud or a slowly-rotating circumstellar envelope that harbors the H _ { 2 } O maser source .