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Plumas de eyección de alta entropía en Casiopea A por convección impulsada por neutrinos
Toshiki Sato1,2,3,4, Keiichi Maeda5, Shigehiro Nagataki6,7
1RIKEN, Wako, Japan. toshiki.sato@rikkyo.ac.jp.
Nature
|April 22, 2021
Resumen
Las explosiones masivas de estrellas pueden involucrar plumas de alta entropía, como lo sugieren las observaciones de titanio y cromo en Cassiopeia A. Estos hallazgos apoyan el modelo de motor de supernova convectiva, crucial para comprender la evolución estelar y la síntesis de elementos.
Área de la Ciencia:
- La astrofísica
- La astrofísica nuclear
- Evolución estelar
Sus antecedentes:
- Las simulaciones multidimensionales sugieren que las plumas flotantes de alta entropía ayudan a las explosiones de estrellas masivas.
- Cassiopeia Un remanente de supernova exhibe estructuras de gas ricas en hierro que se asemejan a estas plumas predichas.
- La confirmación requiere la detección de elementos sintetizados durante la combustión nuclear de alta entropía (congelación rica en alfa).
Objetivo del estudio:
- Para detectar y confirmar la presencia de elementos específicos sintetizados mediante el congelamiento rico en alfa en Cassiopeia A.
- Para proporcionar evidencia observacional de las plumas de eyección de alta entropía en las supernovas de estrellas masivas.
- Para validar los modelos teóricos de las explosiones de supernovas y la nucleosíntesis.
Principales métodos:
- Ejecto de alta velocidad y rico en hierro observado en Cassiopeia A.
- Se analizaron las proporciones de abundancia de titanio (Ti) y cromo (Cr) estables con respecto al hierro (Fe).
- Comparó las relaciones elementales observadas con las predicciones de los modelos de nucleosíntesis, específicamente el congelamiento rico en alfa.
Principales resultados:
- Se ha detectado titanio (Ti) y cromo (Cr) estables a >5 desviaciones estándar significativas en los eyectos de Cassiopeia A.
- Las relaciones de masa Ti/Fe y Cr/Fe observadas son consistentes con las predicciones que requieren una congelación rica en alfa.
- La composición del metal coincide con las predicciones para neutrinos procesados, rico en protones eyecta.
Conclusiones:
- La detección de Ti y Cr proporciona una fuerte evidencia de plumas de eyección de alta entropía en la supernova Cassiopeia A.
- Estas columnas probablemente aumentaron la onda de choque durante la explosión, apoyando el modelo de motor de supernova convectiva.
- Los resultados confirman el papel del calentamiento de neutrinos en la alimentación de las supernovas de estrellas masivas.
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