129 I and 247 Cm in meteorites constrain the last astrophysical source of solar r-process elements
- 26 February 2021
- journal article
- research article
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 371 (6532), 945-948
- https://doi.org/10.1126/science.aba1111
Abstract
The composition of the early Solar System can be inferred from meteorites. Many elements heavier than iron were formed by the rapid neutron capture process (r-process), but the astrophysical sources where this occurred remain poorly understood. We demonstrate that the near-identical half-lives of the radioactive r-process nuclei iodine-129 and curium-247 preserve their ratio, irrespective of the time between production and incorporation into the Solar System. We constrain the last r-process source by comparing the measured meteoritic ratio 129I/247Cm = 438 ± 184 with nucleosynthesis calculations based on neutron star merger and magneto-rotational supernova simulations. Moderately neutron-rich conditions, often found in merger disk ejecta simulations, are most consistent with the meteoritic value. Uncertain nuclear physics data limit our confidence in this conclusion.
Funding Information
- ERC consolidator grant (Project RADIOSTAR, G.A. n. 724560)
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