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Velocidad de flujo hacia afuera cero para el plasma en una capa de transición heliosheath capa de transición
Stamatios M Krimigis1, Edmond C Roelof, Robert B Decker
1Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland 20723, USA. tom.krimigis@jhuapl.edu
Nature
|June 17, 2011
Resumen
La Voyager 1 ha entrado en una capa de plasma de velocidad cero en la heliosfera, lo que sugiere la proximidad a la heliopausa. Este hallazgo desafía los modelos del límite de la cubierta heliocéntrica.
Área de la Ciencia:
- Física del espacio Física del espacio
- Heliofísica es la heliofísica.
- Física del plasma es la física del plasma.
Sus antecedentes:
- La Voyager 1 cruzó el choque de terminación del viento solar en 2004, entrando en la heliosfera.
- La heliosfera es una región de iones y electrones energéticos más allá del choque de terminación.
- Voyager 1 se encuentra actualmente a aproximadamente 22 UA más allá del cruce de choque de terminación.
Objetivo del estudio:
- Para determinar la velocidad en masa del plasma en la heliosfera.
- Para investigar la posición de la Voyager 1 en relación con la heliopausa.
- Para comparar el flujo de plasma observado con los modelos teóricos de la heliosfera.
Principales métodos:
- Utilizando mediciones de la anisotropía de la distribución de iones energéticos.
- Analizando la velocidad de plasma en el plano radial-transverso.
- Seguimiento de cambios en el componente radial de la velocidad del plasma a lo largo del tiempo.
Principales resultados:
- La velocidad radial del plasma ha disminuido linealmente de ~70 km/s a ~0 km/s durante tres años.
- La Voyager 1 se ha mantenido en una región de velocidad radial cero durante los últimos ocho meses.
- La nave espacial parece haber entrado en una capa de transición finita del flujo de plasma.
Conclusiones:
- La entrada de Voyager 1 en una capa de velocidad cero sugiere que está cerca de la heliopausa.
- La capa de transición de flujo observada contradice los modelos que predicen una discontinuidad aguda de la heliopausa.
- Este hallazgo proporciona nuevos conocimientos sobre la estructura de la cubierta heliosférica y su límite con el espacio interestelar.
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