Mechanisms of SiO oxidation: Implications for dust formation

• DOI: 10.3389/fspas.2023.1135156
• Publication Date: 2023-03-02T06:21:38Z
• Authors: Stefan Andersson; David Gobrecht; Rosendo Valero
• Keywords: QC801-809; Astronomy; Geophysics. Cosmic physics; FOS: Physical sciences; QB1-991; DFT; Astrophysics - Astrophysics of Galaxies; 01 natural sciences; 7. Clean energy; circumstellar; Astrophysics - Solar and Stellar Astrophysics; SiO; kinetics; 13. Climate action; Astrophysics of Galaxies (astro-ph.GA); 0103 physical sciences; dust; rate coefficients; Solar and Stellar Astrophysics (astro-ph.SR)

Reactions of SiO molecules have been postulated to initiate efficient formation silicate dust particles in outflows around dying (AGB) stars. Both OH radicals and H 2 O can be present these environments their reactions with the smallest cluster, Si , affect efficiency eventual formation. Rate coefficients gas-phase oxidation clustering SiO, 3 calculated using master equation calculations based on density functional theory calculations. The show that involving are fast. not routes but may under right conditions lead hydroxylated species. reaction O, which has suggested as producing is therefore previously thought. If dissociate form radicals, could accelerated. Kinetics simulations oxygen-rich circumstellar our proposed scheme suggest typical only small amounts formed most silicon remains molecular SiO.