129 I and 247 Cm in meteorites constrain the last astrophysical source of solar r-process elements
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 ( ≃ 15.6  million years ) 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 129 I/ 247 Cm = 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.
Authors:
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Award ID(s):
Publication Date:
NSF-PAR ID:
10251057
Journal Name:
Science
Volume:
371
Issue:
6532
Page Range or eLocation-ID:
945 to 948
ISSN:
0036-8075
National Science Foundation
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5. ABSTRACT

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