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Un candidato a desplazamiento al rojo z ≈ 10 galaxia y rápidos cambios en esa población a la edad de 500 Myr
R J Bouwens1, G D Illingworth, I Labbe
1Department of Astronomy, University of California Santa Cruz, Santa Cruz, California 95064, USA. bouwens@ucolick.org
Nature
|January 29, 2011
Resumen
Los astrónomos buscaron galaxias tempranas usando los datos del campo ultraprofundo del Hubble. Encontraron una posible galaxia con un corrimiento al rojo de ~10, lo que indica un rápido crecimiento de galaxias en el universo temprano.
Área de la Ciencia:
- Evolución cósmica de la evolución cósmica.
- Formación de galaxias Formación de galaxias
- El Universo Temprano Astrofísica Astrofísica
Sus antecedentes:
- Se han identificado más de 6.000 galaxias en desplazamientos al rojo 3-6, que existen entre 900 y 2.000 millones de años después del Big Bang.
- El Hubble Ultra Deep Field (HUDF09) ha proporcionado detecciones de galaxias con desplazamiento al rojo ~8, algunos de los primeros objetos encontrados.
- Observaciones anteriores sugieren que la formación estelar significativa ocurrió en desplazamientos al rojo mayores de 9-10.
Objetivo del estudio:
- Para llevar a cabo una búsqueda ultra-profunda de galaxias con desplazamiento al rojo ~10, aproximadamente 500 millones de años después del Big Bang.
- Para investigar la densidad de la tasa de formación estelar durante la época de reionización.
- Para entender la rápida acumulación de galaxias entre el corrimiento al rojo ~10 y ~8.
Principales métodos:
- Utilizando el conjunto completo de datos HUDF09 de dos años para un análisis en profundidad.
- Realizando una búsqueda ultra-profunda de galaxias candidatas a un corrimiento al rojo de ~10.
- Analizando la densidad de la tasa de formación estelar basada en detecciones de fuentes y no detecciones.
Principales resultados:
- Se identificó una galaxia candidata potencial con desplazamiento al rojo ~10.
- La densidad de la tasa de formación de estrellas en el corrimiento al rojo ~ 10 es aproximadamente el 10% de la de corrimiento al rojo ~ 8.
- Se observó un aumento significativo tanto en la densidad de luminosidad como en la densidad de volumen de las galaxias desde un desplazamiento al rojo de ~10 a ~8.
Conclusiones:
- La acumulación de galaxias fue notablemente rápida entre el corrimiento al rojo ~10 y ~8.
- El período de 100-200 millones de años antes del corrimiento al rojo ~10 fue crítico para el ensamblaje de las primeras galaxias.
- Los hallazgos proporcionan información crucial sobre la formación de galaxias durante la época de reionización.
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