New constraints for supernova models from presolar silicon carbide X grains with very high 26Al/27Al ratios

• Verfasst von: Hoppe, Peter [VerfasserIn]
• Verfasst von: Leitner, Jan [VerfasserIn]
• Verfasst von: Pignatari, Marco [VerfasserIn]
• Verfasst von: Amari, Sachiko [VerfasserIn]
• Titel: New constraints for supernova models from presolar silicon carbide X grains with very high 26Al/27Al ratios
• Verf.angabe: Peter Hoppe, Jan Leitner, Marco Pignatari, and Sachiko Amari
• E-Jahr: 2023
• Jahr: 2023 February 1
• Umfang: 6 S.
• Illustrationen: Illustrationen
• Fussnoten: Die Zahlen "26" und "27" erscheinen im Titel hochgestellt ; Gesehen am 23.11.2023
• Titel Quelle: Enthalten in: The astrophysical journal / 2
• Ort Quelle: London : Institute of Physics Publ., 1995
• Jahr Quelle: 2023
• Band/Heft Quelle: 943(2023), 2, Artikel-ID L22, Seite 1-6
• ISSN Quelle: 2041-8213
• DOI: doi:10.3847/2041-8213/acb157
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1839861738

Abstract

We report C, N, Mg-Al, Si, and S isotope data of six 1-3 μm-sized SiC grains of Type X from the Murchison CM2 chondrite, believed to have formed in the ejecta of core-collapse supernova (CCSN) explosions. Their C, N, and Si isotopic compositions are fully compatible with previously studied X grains. Magnesium is essentially monoisotopic 26Mg which gives clear evidence for the decay of radioactive 26Al. Inferred initial 26Al/27Al ratios are between 0.6 and 0.78 which is at the upper end of previously observed ratios of X grains. Contamination with terrestrial or solar system Al apparently is low or absent, which makes the X grains from this study particularly interesting and useful for a quantitative comparison of Al isotope data with predictions from supernova models. The consistently high 26Al/27Al ratios observed here may suggest that the lower 26Al/27Al ratios of many X grains from the literature are the result of significant Al contamination and in part also of an improper quantification of 26Al. The real dispersion of 26Al/27Al ratios in X grains needs to be explored by future studies. The high observed 26Al/27Al ratios in this work provide a crucial constraint for the production of 26Al in CCSN models. We explored different CCSN models, including both “classical” and H ingestion CCSN models. It is found that the classical models cannot account for the high 26Al/27Al ratios observed here; in contrast, H ingestion models are able to reproduce the 26Al/27Al ratios along with C, N, and Si isotopic ratios reasonably well.