Constraints on metal oxide and metal hydroxide abundances in the winds of AGB stars - Potential detection of FeO in R Dor
| العنوان: | Constraints on metal oxide and metal hydroxide abundances in the winds of AGB stars - Potential detection of FeO in R Dor |
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| المؤلفون: | John M. C. Plane, C. A. Gottlieb, Leen Decin, Taissa Danilovich, Kin Long Kelvin Lee, D. Gobrecht, A. M. S. Richards |
| المصدر: | The Astrophysical Journal Decin, L, Danilovich, T, Gobrecht, D, Plane, J M C, Richards, A M S, Gottlieb, C A & Lee, K L K 2018, ' Constraints on Metal Oxide and Metal Hydroxide Abundances in the Winds of AGB Stars : Potential Detection of FeO in R Dor ', Astrophysical Journal, vol. 855, no. 2, 113 . https://doi.org/10.3847/1538-4357/aaab6a |
| بيانات النشر: | arXiv, 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | Astrochemistry, Metal hydroxide, interferometers [instrumentation], Oxide, Analytical chemistry, FOS: Physical sciences, 01 natural sciences, Submillimeter Array, circumstellar matter, Metal, chemistry.chemical_compound, 0103 physical sciences, Asymptotic giant branch, 14. Life underwater, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, 010304 chemical physics, astrochemistry, individual (IK Tau and R Dor) [stars], Astronomy and Astrophysics, mass-loss [stars], AGB and post-AGB [stars], Stars, Astrophysics - Solar and Stellar Astrophysics, chemistry, 13. Climate action, Space and Planetary Science, Excited state, visual_art, visual_art.visual_art_medium |
| الوصف: | Using ALMA, we observed the stellar wind of two oxygen-rich Asymptotic Giant Branch (AGB) stars, IK Tau and R Dor, between 335 and 362 GHz. One aim was to detect metal oxides and metal hydroxides (AlO, AlOH, FeO, MgO, MgOH), some of which are thought to be direct precursors of dust nucleation and growth. We report on the potential first detection of FeO (v=0, Omega=4, J=11-10) in RDor (mass-loss rate, Mdot, ~1e-7 Msun/yr). The presence of FeO in IK Tau (Mdot~5e-6 Msun/yr) cannot be confirmed due to a blend with 29SiS, a molecule that is absent in R Dor. The detection of AlO in R Dor and of AlOH in IK Tau was reported earlier by Decin et al. (2017). All other metal oxides and hydroxides, as well as MgS, remain undetected. We derive a column density N(FeO) of 1.1+/-0.9e15 cm^{-2} in R Dor, or a fractional abundance [FeO/H]~1.5e-8 accounting for non-LTE effects. The derived fractional abundance [FeO/H] is a factor ~20 larger than conventional gas-phase chemical kinetic predictions. This discrepancy may be partly accounted for by the role of vibrationally excited OH in oxidizing Fe, or may be evidence for other currently unrecognised chemical pathways producing FeO. Assuming a constant fractional abundance w.r.t. H_2, the upper limits for the other metals are [MgO/H_2] 14 pages (including appendices), accepted for publication by Astrophysical Journal |
| وصف الملف: | application/pdf |
| تدمد: | 1538-3881 0067-0049 0004-6361 0004-637X |
| DOI: | 10.48550/arxiv.1801.09302 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3c9c892a7d8ca59a63a32715bc693f17 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....3c9c892a7d8ca59a63a32715bc693f17 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15383881 00670049 00046361 0004637X |
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| DOI: | 10.48550/arxiv.1801.09302 |