History of two mass loss processes in VY CMa.
Proc Int Astron Union
; 6692023 Jan.
Article
em En
| MEDLINE
| ID: mdl-38125701
ABSTRACT
Red Supergiant stars (RSGs) are known to eject large amounts of material during this evolutionary phase. However, the processes powering the mass ejection in low- and intermediate-mass stars do not work for RSGs and the mechanism that drives the ejection remains unknown. Different mechanisms have been proposed as responsible for this mass ejection including Alfvén waves, large convective cells, and magnetohydrodynamical (MHD) disturbances at the photosphere, but so far little is known about the actual processes taking place in these objects. Here we present high angular resolution interferometric ALMA maps of VY CMa continuum and molecular emission, which resolve the structure of the ejecta with unprecedented detail. We reconstructed the 3D structure of the gas traced by the different species. It allowed us to study the morphology and kinematics of the gas traced by the different species surrounding VY CMa. Two types of ejecta are clearly observed extended, irregular, and vast ejecta surrounding the star that are carved by localized fast outflows. The structure of the outflows is found to be particularly flat. We present a 3D reconstruction of these outflows and proof of the carving. This indicates that two different mass loss processes take place in this massive star. We tentatively propose the physical cause for the formation of both types of structures. These results provide essential information on the mass loss processes of RSGs and thus of their further evolution.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Proc Int Astron Union
Ano de publicação:
2023
Tipo de documento:
Article