CO J=3-2 Emission from the "Water Fountain" Sources IRAS 16342-3814 and IRAS 18286-0959

Abstract

We observed CO J=3-2 emission from the "water fountain" sources, which exhibit high-velocity collimated stellar jets traced by water 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+/-6 km/s and an intensity peak at VLSR = 50+/-2 km/s. The mass loss rate of the star is estimated to be ~2.9x10^-5 M_sun/yr. 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+/-0.2 km/s, 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 water maser source.

10 pages, 4 figure, accepted for publication in the Publications of the Astronomical Society of Japan, Vol. 61, No.6, 2009 December issue

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Cited by in corpus (9)

• High Velocity Precessing Jets from the Water Fountain IRAS 18286-0959 Revealed by VLBA Observations
• The first "water fountain" collimated outflow in a planetary nebula
• Annual Parallax Distance and Secular Motion of the Water Fountain Source IRAS 18286-0959
• Sensitive CO and 13CO survey of water fountain stars. Detections towards IRAS 18460-0151 and IRAS 18596+0315
• Extremely Strong ^{13}CO J=3-2 Line in the "Water Fountain" IRAS 16342-3814: Evidence for the Hot-Bottom Burning
• FLASHING: New high-velocity H${}_2$O masers in IRAS 18286$-$0959
• A Fast bipolar H2 outflow from IRAS 16342-3814: an old star reliving its youth
• CO observations of water-maser post-AGB stars and detection of a high-velocity outflow in IRAS 15452-5459
• Early Science with the Large Millimetre Telescope: Molecules in the Extreme Outflow of a proto-Planetary Nebula