Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/114747
DC Field | Value | Language |
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dc.contributor.author | Andersson, Stefan | - |
dc.contributor.author | Gobrecht, David | - |
dc.contributor.author | Valero, Rosendo | - |
dc.date.accessioned | 2024-04-08T11:44:25Z | - |
dc.date.available | 2024-04-08T11:44:25Z | - |
dc.date.issued | 2023-03-09 | - |
dc.identifier.issn | 2296-987X | pt |
dc.identifier.uri | https://hdl.handle.net/10316/114747 | - |
dc.description | 10 pages, 13 figures | pt |
dc.description.abstract | Reactions of SiO molecules have been postulated to initiate efficient formation of silicate dust particles in outflows around dying (AGB) stars. Both OH radicals and H$_2$O molecules can be present in these environments and their reactions with SiO and the smallest SiO cluster, Si$_2$O$_2$, affect the efficiency of eventual dust formation. Rate coefficients of gas-phase oxidation and clustering reactions of SiO, Si$_2$O$_2$ and Si$_2$O$_3$ have been calculated using master equation calculations based on density functional theory calculations. The calculations show that the reactions involving OH are fast. Reactions involving H$_2$O are not efficient routes to oxidation but may under the right conditions lead to hydroxylated species. The reaction of Si$_2$O$_2$ with H$_2$O, which has been suggested as efficient producing Si$_2$O$_3$, is therefore not as efficient as previously thought. If H$_2$O molecules dissociate to form OH radicals, oxidation of SiO and dust formation could be accelerated. Kinetics simulations of oxygen-rich circumstellar environments using our proposed reaction scheme suggest that under typical conditions only small amounts of SiO$_2$ and Si$_2$O$_2$ are formed and that most of the silicon remains as molecular SiO. | pt |
dc.language.iso | eng | pt |
dc.relation | Knut and Alice Wallenberg foundation (research grant KAW 2020.0081) | pt |
dc.rights | openAccess | pt |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | pt |
dc.subject | SiO | pt |
dc.subject | circumstellar | pt |
dc.subject | dust | pt |
dc.subject | DFT | pt |
dc.subject | rate coefficients | pt |
dc.subject | kinetics | pt |
dc.title | Mechanisms of SiO oxidation: Implications for dust formation | pt |
dc.type | article | - |
degois.publication.firstPage | 1135156 | pt |
degois.publication.title | Frontiers in Astronomy and Space Sciences | pt |
dc.peerreviewed | yes | pt |
dc.identifier.doi | 10.3389/fspas.2023.1135156 | pt |
degois.publication.volume | 10 | pt |
dc.date.embargo | 2023-03-09 | * |
uc.date.periodoEmbargo | 0 | pt |
item.cerifentitytype | Publications | - |
item.languageiso639-1 | en | - |
item.fulltext | Com Texto completo | - |
item.grantfulltext | open | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | article | - |
Appears in Collections: | FCTUC Química - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
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Mechanisms of SiO oxidation Implications for dust formation.pdf | 2.33 MB | Adobe PDF | View/Open |
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