| Title: |
The occurrence and impact of carbon-oxygen shell mergers in massive stars |
| Authors: |
Roberti L.; Pignatari M.; Brinkman H. E.; Jeena S. K.; Sieverding A.; Falla A.; Limongi M.; Chieffi A.; Lugaro M. |
| Contributors: |
Roberti, L.; Pignatari, M.; Brinkman, H. E.; Jeena, S. K.; Sieverding, A.; Falla, A.; Limongi, M.; Chieffi, A.; Lugaro, M. |
| Publisher Information: |
EDP Sciences; Les Ulis, France |
| Publication Year: |
2025 |
| Collection: |
Sapienza Università di Roma: CINECA IRIS |
| Subject Terms: |
convection; nuclear reaction; nucleosynthesi; abundance; stellar evolution; massive star; supernovae |
| Description: |
Context. In their final stages before undergoing a core-collapse supernova, massive stars may experience mergers between internal shells where carbon (C) and oxygen (O) are consumed as fuels for nuclear burning. This interaction, known as a C-O shell merger, can dramatically alter the internal structure of the star, leading to peculiar nucleosynthesis and potentially influencing the supernova explosion and the propagation of the subsequent supernova shock. Aims. Our understanding of the frequency and consequences of C-O shell mergers remains limited. This study aims to identify, for the first time, early diagnostics in the stellar structure that lead to C-O shell mergers in more advanced stages. We also assess their role in shaping the chemical abundances in the most metal poor stars of the Galaxy. Methods. We analyzed a set of 209 stellar evolution models available in the literature, with different initial progenitor masses and metallicities. We then compared the nucleosynthetic yields from a subset of these models with the abundances of odd-Z elements in metal-poor stars. Results. We find that the occurrence of C-O shell mergers in stellar models can be predicted with a good approximation based on the outcomes of the central He burning phase, specifically, from the CO core mass (MCO) and the 12C central mass fraction (XC12): 90% of models with a C-O merger have XC12 |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
info:eu-repo/semantics/altIdentifier/wos/WOS:001510826300008; volume:698; issue:A&A; firstpage:1; lastpage:9; numberofpages:9; journal:ASTRONOMY & ASTROPHYSICS; https://hdl.handle.net/11573/1753413 |
| DOI: |
10.1051/0004-6361/202554461 |
| Availability: |
https://hdl.handle.net/11573/1753413; https://doi.org/10.1051/0004-6361/202554461 |
| Rights: |
info:eu-repo/semantics/openAccess ; license:Creative commons ; license uri:http://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.82C71B21 |
| Database: |
BASE |