Keplerian disks and out flows in binary post-AGB stars
The evolution of intermediate mass stars (0:8 < M < 8M ) in their last stages is fast. In these phases the star evolves from the asymptotic giant branch (AGB) over the post-AGB star phase towards the central star of planetary nebula (CSPN) phase. At the end of the AGB phase, the star exhibits...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/4208 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/4208 |
| Access Level: | acceso abierto |
| Palabra clave: | 524.38(043.2) Double stars Estrellas dobles Astronomía (Física) |
| Sumario: | The evolution of intermediate mass stars (0:8 < M < 8M ) in their last stages is fast. In these phases the star evolves from the asymptotic giant branch (AGB) over the post-AGB star phase towards the central star of planetary nebula (CSPN) phase. At the end of the AGB phase, the star exhibits high mass-loss rates, up to 10- 4 M a-1.The star begins the post-AGB stage after having expelled most of its stellar envelope. The nebula around a post-AGB star is known as a pre-planetary nebula (pPN), and most of them typically exhibit fast bipolar out ows. We focus on a certain class of post-AGB stars that are part of a binary system. These binary systems present orbital periods between 100 and 3 000 days and separations smaller than 5AU, avoiding (or rapidly going through) the common envelope phase. Their remarkable near-infrared excess in the spectral energy distribution (SED) is an observational probe for the presence of disks around the binary system. This excess at IR wavelengths is indicative of the presence of hot dust produced by the inner regions of these disks. They are formed during the binary interaction. They are stable structures and there are several evidences that prove it, such as the detection of Keplerian dynamics or the presence of highly processed dust grains... |
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