129I and 247Cm in meteorites constrain the last astrophysical source of solar r-process elements

Côté, Benoit; Eichler, Marius; Yagüe, Andrés; Vassh, Nicole; R. Mumpower, Matthew; Világos, Blanka; Soós, Benjámin; Arcones, Almudena; M. Sprouse, Trevor; Surman, Rebecca; Pignatari, Marco; Pető, Mária K.; Wehmeyer, Benjamin; Rauscher, Thomas; Lugaro, Maria

Abstract

Meteoritic analysis demonstrates that radioactive nuclei heavier than iron were present in the early Solar System. Among them, $^{129}$I and $^{247}$Cm both have a rapid neutron-capture process ($r$ process) origin and decay on the same timescale ($\simeq$ 15.6 Myr). We show that the $^{129}$I/$^{247}$Cm abundance ratio in the early Solar System (438$\pm$184) is immune to galactic evolution uncertainties and represents the first direct observational constraint for the properties of the last $r$-process event that polluted the pre-solar nebula. We investigate the physical conditions of this event using nucleosynthesis calculations and demonstrate that moderately neutron-rich ejecta can produce the observed ratio. We conclude that a dominant contribution by exceedingly neutron-rich ejecta is highly disfavoured.

Citation

Côté, B., Eichler, M., Yagüe, A., Vassh, N., R. Mumpower, M., Világos, B., …Lugaro, M. (2021). 129I and 247Cm in meteorites constrain the last astrophysical source of solar r-process elements. Science, 371(6532), 945-948. https://doi.org/10.1126/science.aba1111

• Journal Article Type: Article
• Acceptance Date: Jan 25, 2021
• Online Publication Date: Feb 26, 2021
• Publication Date: Feb 26, 2021
• Deposit Date: Dec 17, 2020
• Publicly Available Date: Mar 22, 2021
• Journal: Science
• Print ISSN: 0036-8075
• Publisher: American Association for the Advancement of Science
• Peer Reviewed: Peer Reviewed
• Volume: 371
• Issue: 6532
• Pages: 945-948
• DOI: https://doi.org/10.1126/science.aba1111
• Keywords: Solar and Stellar Astrophysics; High Energy Astrophysical Phenomena; Nuclear Theory
• Public URL: https://hull-repository.worktribe.com/output/3523740