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129 y 247 cm en los meteoritos limitan la última fuente astrofísica de los elementos del proceso solar
Benoit Côté1,2,3, Marius Eichler4, Andrés Yagüe López5
1Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network, Konkoly Observatory, 1121 Budapest, Hungary. benoit.cote@csfk.org.
Science (New York, N.Y.)
|February 26, 2021
Resumen
Los meteoritos revelan la composición temprana del Sistema Solar. La proporción de yodo-129 a curio-247 en los meteoritos sugiere que las fusiones de estrellas de neutrones produjeron elementos pesados a través del proceso de captura rápida de neutrones (proceso r).
Área de la Ciencia:
- Cosmoquímica y Astrofísica Nuclear
- Investigando los orígenes de los elementos pesados en el Sistema Solar
Sus antecedentes:
- Los meteoritos proporcionan una visión crucial de la composición química del sistema solar temprano.
- El proceso de captura rápida de neutrones (proceso r) es responsable de sintetizar elementos más pesados que el hierro, pero su ubicación astrofísica sigue siendo incierta.
Objetivo del estudio:
- Para restringir el sitio astrofísico del último evento de proceso r anterior a la formación del Sistema Solar.
- Para utilizar la proporción conservada de yodo-129 (129I) y el curio-247 (247Cm) en los meteoritos como marcador.
Principales métodos:
- Se midió la relación 129I/247Cm en los meteoritos.
- Comparó la relación meteorítica con los cálculos de la nucleosíntesis de la fusión de estrellas de neutrones y las simulaciones de supernovas magneto-rotacionales.
- Aprovechó las semividas casi idénticas de 129I y 247Cm para preservar su relación de producción.
Principales resultados:
- La relación meteorítica medida de 129I/247Cm fue determinada como 438 ± 184.
- Los cálculos de la nucleosíntesis indican que las condiciones moderadamente ricas en neutrones son más consistentes con esta relación observada.
- Estas condiciones se simulan con frecuencia en el eyecto de los discos de fusión de estrellas de neutrones.
Conclusiones:
- Las fusiones de estrellas de neutrones son una fuente probable de los elementos del proceso r incorporados en el Sistema Solar temprano.
- El estudio destaca la importancia de las relaciones isotópicas en los meteoritos para comprender la nucleosíntesis.
- Las incertidumbres en los datos de la física nuclear limitan actualmente la confianza en estas conclusiones.
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