Projektbeschreibung
Die Modellierung von Staubbildung und -zusammensetzung im Umfeld sterbender Sterne
Bei Sternen wie unserer Sonne nennt man die letzte Entwicklungsphase den asymptotischen Riesenast. Im Laufe dieser Phase sinkt deren Temperatur so sehr, dass Staub anfängt, in einer ausgedehnten zirkumstellaren Hülle zu kondensieren. Bislang ist wenig über die Bildung, Struktur und chemische Zusammensetzung von Staub in Scheiben auf dem asymptotischen Riesenast bekannt. Das EU-finanzierte Projekt ICEDRAGON wird Modelle zur Untersuchung der Staubkörner sowie der Auswirkungen der Gasphasenzusammensetzung auf die zirkumstellare Hülle entwickeln. Die Analyse der Staubkörner sollte der Astrophysik einen Einblick in die stürmischen inneren Abläufe der letzten Atemzüge der zirkumstellaren Hülle um sterbende Sterne verschaffen und könnte klären, wie interstellares Material angesammelt und verarbeitet wird, um neue Planeten zu schaffen.
Ziel
In their twilight years, solar-like stars in the asymptotic giant branch (AGB) phase enrich the interstellar medium (ISM) with fresh material (gas and dust) for new stars and planets. AGB stars lose their outer layers to the ISM through a stellar outflow or wind, forming an extended circumstellar envelope (CSE). The wind is thought to be dust-driven, with dust grains forming close to the star. State-of-the-art observations have revealed the composition of the inner CSE, allowing the first identification of gas-phase seeds for dust grains, and the presence of disks around AGB stars. Despite major knowledge gains over the past three decades, it is still not fully understood how dust forms, grows, and drives the stellar wind, limiting our understanding of both stellar evolution and the chemical enrichment of the ISM. Moreover, the structure and chemistry of AGB disks is unknown; if similar to protoplanetary disks, second generation planet formation may be possible therein.
Solving these puzzles requires new and sophisticated models that connect dust formation with chemistry and couple gas and dust chemistry throughout the wind and in the disk. With ‘ICE and Dust Reactions in AGB Gaseous Outflows and disks with Nucleation’ (ICEDRAGON), we will develop the first models that link the chemistry throughout the whole CSE and the first chemical model of an AGB disk. The novel models will allow us to study, for the first time, the organic refractory feedback of dust grains delivered to the ISM and the role of dust formation on the gas-phase chemistry throughout the CSE. This is necessary to deduce the physics behind the wind launching mechanism, that is encoded in the observed composition. The AGB disk model will provide the first answers to the viability of secondary planet formation. The synergy between fellow and host is ideal for this astrochemical (and fundamentally interdisciplinary) project, as it combines their respective expertise in chemical modelling.
Wissenschaftliches Gebiet
Schlüsselbegriffe
Programm/Programme
Thema/Themen
Aufforderung zur Vorschlagseinreichung
Andere Projekte für diesen Aufruf anzeigenFinanzierungsplan
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Koordinator
LS2 9JT Leeds
Vereinigtes Königreich