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Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
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Confirmación espectroscópica de una galaxia con desplazamiento al rojo z = 8.6
M D Lehnert1, N P H Nesvadba, J-G Cuby
1GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 5 Place Jules Janssen, 92190 Meudon, France. matthew.lehnert@obspm.fr
Nature
|October 22, 2010
Resumen
Los astrónomos detectaron fotones Lyman-alfa (Lyα) de una galaxia menos de 600 millones de años después del Big Bang. Esta galaxia, con desplazamiento al rojo z = 8.5549, ofrece información crucial sobre el Universo temprano.
Área de la Ciencia:
- Cosmología y astronomía extragaláctica.
- Estudios del Universo Temprano estudian el Universo Temprano.
- Evolución de las galaxias y reionización.
Sus antecedentes:
- Las primeras estrellas en las galaxias primitivas impactaron significativamente en el Universo ionizando el medio intergaláctico.
- La reionización, un proceso complejo, se completó alrededor de mil millones de años después del Big Bang (redshift z ≈ 6).
- La detección de fotones ionizantes de galaxias lejanas limita las fuentes responsables de la reionización.
Objetivo del estudio:
- Para detectar los fotones Lyman-alfa (Lyα) de las galaxias en el Universo muy temprano.
- Poner restricciones en el tiempo, la ubicación y la naturaleza de las fuentes de reionización.
- Para identificar la galaxia más distante conocida en el momento del estudio.
Principales métodos:
- Observación y detección de las líneas de emisión Lyman-alfa (Lyα) de las galaxias.
- Análisis espectroscópico para determinar el corrimiento al rojo y la distancia.
- Comparación con los objetos más distantes previamente conocidos.
Principales resultados:
- Detección de fotones Lyα de la galaxia UDFy-38135539 en un desplazamiento al rojo de z = 8.5549 ± 0.0002.
- Esta galaxia es el objeto más distante conocido en el momento del informe, observado menos de 600 millones de años después del Big Bang.
- La única fuente detectada es insuficiente para ionizar el volumen necesario para el escape de Lyα, lo que implica contribuciones de galaxias más débiles cercanas.
Conclusiones:
- La galaxia detectada proporciona evidencia de la formación temprana de galaxias y su papel en la reionización cósmica.
- La reionización probablemente involucró una contribución colectiva de numerosas galaxias, posiblemente más débiles.
- Se necesitan más observaciones para comprender completamente el proceso de reionización y la contribución de las poblaciones débiles de galaxias.
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