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Un papel para la auto-gravedad en múltiples escalas de longitud en el proceso de formación estelar
Alyssa A Goodman1, Erik W Rosolowsky, Michelle A Borkin
1Initiative in Innovative Computing at Harvard, Cambridge, Massachusetts 02138, USA. agoodman@cfa.harvard.edu
Nature
|January 6, 2009
Resumen
La auto-gravedad es crucial para la formación de estrellas dentro de las nubes moleculares. El análisis de la nube L1448 muestra que la auto-gravedad impacta significativamente en la formación de estrellas a través de varias escalas, particularmente para núcleos pre-estelares.
Área de la Ciencia:
- La astrofísica es la astrofísica.
- Formación Estelar Formación Estelar.
- La astrofísica computacional es una astrofísica computacional.
Sus antecedentes:
- Se sabe que la autogravedad es crítica en las últimas etapas de la formación estelar, impulsando el colapso de núcleos densos en sistemas de estrella más disco.
- El papel de la auto-gravedad en etapas anteriores y escalas más grandes (por ejemplo, ~ 1 parsec) dentro de las nubes moleculares sigue siendo incierto.
- Algunas simulaciones sugieren que la fragmentación turbulenta por sí sola puede establecer la función de masa inicial estelar sin tener en cuenta la auto-gravedad.
Objetivo del estudio:
- Para investigar el papel de la auto-gravedad a través de un rango de escalas en las nubes moleculares durante el proceso de formación de estrellas.
- Para analizar la nube molecular L1448 utilizando análisis de dendrogramas para identificar estructuras de auto-gravitación.
- Para comparar hallazgos observacionales con simulaciones que incluyen o excluyen la auto-gravedad.
Principales métodos:
- Utilizó el análisis del dendrograma (diagrama de árbol jerárquico) en los datos de observación de la nube molecular L1448, trazada por (13) CO.
- Se analizaron los picos de emisión de polvo para identificar núcleos preestelares compactos.
- Comparó los resultados observacionales con un análisis de dendrogramas de una simulación sin auto-gravedad.
Principales resultados:
- La autogravedad juega un papel importante en las escalas observadas en la nube molecular L1448, aunque no uniformemente.
- Más del 90% de los núcleos pre-estelares se encuentran dentro de estructuras auto-gravitatorias identificadas por el análisis del dendrograma.
- Las simulaciones sin auto-gravedad, mientras imitan algunos espectros observados, muestran una proporción mucho mayor de gas que parece auto-gravitarse de lo observado.
Conclusiones:
- Un capullo auto-gravitatorio parece ser una condición crítica para la existencia de núcleos pre-estelares y estrellas en formación.
- El importante papel de la gravedad en las simulaciones de "no auto-gravitación" indica posibles inconsistencias en sus supuestos y salidas.
- Incluir la auto-gravedad es esencial para las simulaciones realistas de la formación estelar en escalas subparsec.
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