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Direct Imaging of Laser-driven Ultrafast Molecular Rotation
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Un enorme depósito de gas molecular de baja excitación con alto corrimiento al rojo
P Papadopoulos1, R Ivison, C Carilli
1Leiden Observatory, PO Box 9513, 2300 Leiden, The Netherlands.
Nature
|May 9, 2001
Resumen
Los astrónomos descubrieron un gas molecular sustancial de baja excitación en un cuásar de alto desplazamiento al rojo utilizando líneas de monóxido de carbono (CO). Este hallazgo sugiere que las observaciones anteriores pueden haber subestimado significativamente el contenido de gas molecular de las primeras galaxias.
Área de la Ciencia:
- La astronomía y la astrofísica.
- Estudios de gas y polvo cósmico.
- Evolución de la galaxia Evolución de la galaxia.
Sus antecedentes:
- El hidrógeno molecular (H2) alimenta la formación estelar y los núcleos galácticos activos (AGN) en galaxias ricas en gas.
- Las líneas de emisión de monóxido de carbono (CO) trazan las propiedades moleculares del gas.
- Anteriormente, solo se podían observar transiciones más altas de CO en galaxias con alto desplazamiento al rojo, lo que potencialmente subestimaba la masa molecular del gas.
Objetivo del estudio:
- Investigar la presencia y las propiedades del gas molecular de baja excitación en galaxias de alto desplazamiento al rojo.
- Para determinar si las observaciones anteriores subestimaron el contenido total de gas molecular.
- Explorar el papel del gas molecular en la evolución temprana de las galaxias.
Principales métodos:
- Utilizó las líneas de excitación más bajas de 12CO (J = 1 --> 0 y J = 2 --> 1) para observar el cuásar APM08279+5255 con desplazamiento al rojo z = 3.91.
- Mapeó la distribución del gas molecular alrededor del cuásar.
- Se analizaron los niveles de excitación y la masa del gas molecular detectado.
Principales resultados:
- Descubrieron grandes cantidades de gas molecular de baja excitación alrededor del cuásar APM08279+5255.5.
- Confirmó la presencia de gas caliente y denso cerca del núcleo del cuásar.
- Reveló un reservorio de gas molecular extendido de 10 a 100 veces más masivo que el gas previamente detectado.
Conclusiones:
- Cantidades significativas de gas molecular de baja excitación pueden ser comunes en galaxias de alto desplazamiento al rojo (z > 3).
- Las observaciones anteriores que utilizaron transiciones más altas de CO probablemente subestimaron la masa total de gas molecular en el Universo temprano.
- Este descubrimiento tiene importantes implicaciones para la comprensión de la formación y evolución de las galaxias a altos desplazamientos al rojo.
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