Interferometric confirmation of 'water fountain' candidates
Water fountain stars (WFs) are evolved objects with watermasers tracing high-velocity jets (upto several hundreds of km s). They could represent one of the first manifestations of collimatedmass-loss in evolved objects and thus be a key to understanding the shaping mechanismsof planetary nebulae. On...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/370495 |
| Acceso en línea: | http://hdl.handle.net/10261/370495 |
| Access Level: | acceso abierto |
| Palabra clave: | Masers Stars: AGB and post-AGB Stars: winds, outflows. |
| Sumario: | Water fountain stars (WFs) are evolved objects with watermasers tracing high-velocity jets (upto several hundreds of km s). They could represent one of the first manifestations of collimatedmass-loss in evolved objects and thus be a key to understanding the shaping mechanismsof planetary nebulae. Only 13 objects had been confirmed so far as WFs with interferometerobservations. We present new observations with the Australia Telescope Compact Array andarchival observations with the Very Large Array of four objects that are considered to be WFcandidates, mainly based on single-dish observations. We confirm IRAS 17291-2147 andIRAS 18596+0315 (OH 37.1-0.8) as bona fide members of the WF class, with high-velocitywater maser emission consistent with tracing bipolar jets. We argue that IRAS 15544-5332has been wrongly considered as aWF in previous works, since we see no evidence in our datanor in the literature that this object harbours high-velocity water maser emission. In the caseof IRAS 19067+0811, we did not detect any water maser emission, so its confirmation as aWF is still pending. With the result of this work, there are 15 objects that can be consideredconfirmed WFs. We speculate that there is no significant physical difference between WFsand obscured post-AGB stars in general. The absence of high-velocity water maser emissionin some obscured post-AGB stars could be attributed to a variability or orientation effect. © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society |
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