557 GHz Observations of Water Vapor Outflow from VY Canis Majoris and W Hydrae
Abstract
We report the first detection of thermal water vapor emission in the 557 GHz, 110-101 ground-state transition of ortho-H2O toward VY Canis Majoris. In observations obtained with the Submillimeter Wave Astronomy Satellite, we measured a flux of ~450 Jy, in a spectrally resolved line centered on a velocity vLSR=25 km s-1 with an FWHM of ~35 km s-1, somewhat dependent on the assumed line shape. We analyze the line shape in the context of three different radial outflow models for which we provide analytical expressions. We also detected a weaker 557 GHz emission line from W Hydrae. We find that these and other H2O emission-line strengths scale as suggested by Zubko and Elitzur.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2002
- DOI:
- 10.1086/339365
- arXiv:
- arXiv:astro-ph/0112546
- Bibcode:
- 2002ApJ...565L.105H
- Keywords:
-
- Stars: Circumstellar Matter;
- Infrared: Stars;
- Stars: Individual: Constellation Name: VY Canis Majoris;
- Stars: Individual: Constellation Name: W Hydrae;
- Stars: Mass Loss;
- Stars: Winds;
- Outflows;
- Astrophysics
- E-Print:
- Astrophysical Journal Letters, accepted