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Spin-down por la acción de la dínamo en las capas estelares radiativas simuladas
Ludovic Petitdemange1, Florence Marcotte2, Christophe Gissinger3,4
1Laboratoire d'Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA), Observatoire de Paris, Paris Sciences & Lettres (PSL) Research University, French National Centre for Scientific Research (CNRS), Sorbonne Université, Paris, France.
Science (New York, N.Y.)
|January 19, 2023
Resumen
La dinámica de rotación estelar interna es crucial para la evolución de las estrellas, pero se entiende mal. Nuestras simulaciones revelan un mecanismo de dínamo magnético que mejora el transporte del momento angular y genera fuertes campos magnéticos internos en las estrellas.
Área de la Ciencia:
- Astrofísica estelar
- Magnetohidrodinámica
- Física computacional
Sus antecedentes:
- La evolución de las estrellas se rige por la dinámica de rotación interna, que afecta a los procesos de transporte y mezcla.
- El origen de los campos magnéticos en los interiores estelares radiativos y su papel en el transporte del momento angular siguen sin estar claros.
- Comprender el magnetismo estelar es clave para explicar las propiedades estelares observadas.
Objetivo del estudio:
- Para investigar la generación de campos magnéticos en el interior estelar radiativo.
- Explorar el papel de los campos magnéticos en el momento angular y el transporte de elementos químicos.
- Identificar el mecanismo responsable de la acción del dínamo estelar en las zonas radiativas.
Principales métodos:
- Simulaciones numéricas globales de los interiores estelares.
- Análisis de las transiciones del flujo de fluidos de los estados laminares a los turbulentos.
- Modelado de la generación y el transporte de campos magnéticos.
Principales resultados:
- Se identificó una transición subcrítica del flujo laminar a la turbulencia, impulsada por la generación de dínamo magnético.
- El dínamo simulado exhibe propiedades consistentes con el mecanismo del dínamo de Tayler-Spruit.
- Se generan campos magnéticos toroidales fuertes y profundos y, posteriormente, son protegidos por las capas externas estelares.
Conclusiones:
- El mecanismo de dinamo de Tayler-Spruit proporciona una explicación viable para el transporte de momento angular mejorado en las zonas radiativas estelares.
- Este mecanismo puede generar campos magnéticos internos significativos en las estrellas sin un campo magnético de superficie detectable.
- Los hallazgos ofrecen información sobre la dinámica interna poco comprendida que influye en la evolución estelar.
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