Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-02-03
Astronomy and Astrophysics
Astrophysics
47 pages, 9 figures, 4 tables, accepted by ApJ
Scientific paper
10.1086/511383
We present the results of 22 GHz H_2O maser observations of a sample of 85 post-Asymptotic Giant Branch (post-AGB) candidate stars, selected on the basis of their OH 1612 MHz maser and far-infrared properties. All sources were observed with the Tidbinbilla 70-m radio telescope and 21 detections were made. 86 GHz SiO Mopra observations of a subset of the sample are also presented. Of the 21 H_2O detections, 15 are from sources that are likely to be massive AGB stars and most of these show typical, regular H_2O maser profiles. In contrast, nearly all the detections of more evolved stars exhibited high-velocity H_2O maser emission. Of the five sources seen, v223 (W43A, IRAS 18450-0148) is a well known `water-fountain' source which belongs to a small group of post-AGB stars with highly collimated, high-velocity H_2O maser emission. A second source in our sample, v270 (IRAS 18596+0315), is also known to have high-velocity emission. We report the discovery of similar emission from a further three sources, d46 (IRAS 15445-5449), d62 (IRAS 15544-5332) and b292 (IRAS 18043-2116). The source d46 is an evolved post-AGB star with highly unusual maser properties. The H_2O maser emission from d62 is probably associated with a massive star. The source b292 is a young post-AGB star that is highly likely to be a water-fountain source, with masers detected over a velocity range of 210 km s^{-1}.
Chapman Jessica M.
Deacon Rachel M.
Green Andrew J.
Sevenster Maartje N.
No associations
LandOfFree
H2O Maser Observations of Candidate Post-AGB Stars and Discovery of Three High-velocity Water Sources does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with H2O Maser Observations of Candidate Post-AGB Stars and Discovery of Three High-velocity Water Sources, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and H2O Maser Observations of Candidate Post-AGB Stars and Discovery of Three High-velocity Water Sources will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-87213