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Formación estelar masiva dentro del anillo "primordial" de Leo
David A Thilker1, Jennifer Donovan, David Schiminovich
1Center for Astrophysical Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA. dthilker@pha.jhu.edu
Nature
|February 20, 2009
Resumen
El anillo de Leo, una masiva nube de gas, muestra signos de reciente formación estelar, lo que sugiere que puede ser una galaxia enana en formación. Este descubrimiento ofrece información sobre la formación de galaxias en el universo temprano. Palabras clave: anillo de Leo, formación de estrellas, galaxias enanas, formación de galaxias.
Área de la Ciencia:
- La astronomía y la astrofísica.
- Cosmología Cosmología.
- Formación y evolución de las galaxias.
Sus antecedentes:
- Las nubes de hidrógeno atómico neutro intergaláctico (H i) son raras en el Universo local, y se han encontrado pocos ejemplos primordiales.
- El anillo de Leo, una estructura masiva de hidrógeno, es un candidato para tal nube primordial, que anteriormente solo se observaba a través de la emisión de hidrógeno.
Objetivo del estudio:
- Para investigar el anillo de Leo en busca de evidencia de una población estelar y la formación de estrellas en curso.
- Caracterizar las propiedades de cualquier población estelar detectada, incluyendo la metalicidad y la escala de tiempo de formación.
Principales métodos:
- Detección de luz ultravioleta de las subestructuras gaseosas dentro del anillo de Leo.
- Análisis de la fotometría ultravioleta visible para restringir la metalicidad y la duración de la formación estelar.
Principales resultados:
- Detección de luz ultravioleta, lo que indica la reciente formación de estrellas masivas dentro de las subestructuras gaseosas del anillo Leo.
- El color ultravioleta observado sugiere un estallido de formación estelar o una formación estelar continua moderada (aprox. 10^8 años). es decir, 10^8 años).
- La fotometría favorece los modelos de baja metalicidad (Z aprox. Z/50-Z/5), lo que requiere una confirmación espectroscópica.
Conclusiones:
- Las subestructuras del anillo de Leo pueden representar galaxias enanas en formación que carecen de materia oscura, similares a las galaxias enanas de marea pero sin enriquecimiento previo.
- Si es común en el Universo temprano, tales estructuras podrían dar cuenta de una población significativa de galaxias enanas débiles no detectadas, pobres en metales y que carecen de halo.
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