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Un disco de acreción fresco alrededor del agujero negro del Centro Galáctico
Elena M Murchikova1,2, E Sterl Phinney3, Anna Pancoast4
1Institute for Advanced Study, Princeton, NJ, USA. lena@ias.edu.
Nature
|June 7, 2019
Resumen
Los astrónomos detectaron un disco giratorio de gas ionizado cerca del agujero negro supermasivo central de la Vía Láctea, Sagitario A*. Este descubrimiento, utilizando la línea espectral H30α, revela propiedades de gas previamente no restringidas por las observaciones.
Área de la Ciencia:
- Astrofísica y astronomía
- Investigación de agujeros negros
- Dinámica de los gases en los centros galácticos
Sus antecedentes:
- El agujero negro supermasivo central de la Vía Láctea, Sagitario A*, tiene una masa de 4 × 10 ^ 6 masas solares.
- Un depósito de gas caliente y frío rodea a Sagitario A*, pero la masa de gas frío en la zona de acreción del agujero negro permanece sin restricciones.
- Las líneas espectrales de recombinación de hidrógeno ofrecen un método potencial para detectar este gas más frío.
Objetivo del estudio:
- Para tomar una imagen y caracterizar el disco de gas frío y ionizado que rodea a Sagitario A*.
- Para limitar la masa y la densidad de este componente de gas.
- Investigar los procesos físicos que gobiernan el gas en las inmediaciones del agujero negro supermasivo.
Principales métodos:
- Utilizó la radioastronomía de 1,3 milímetros para observar la línea de recombinación de hidrógeno H30α.
- Imagen del disco de gas dentro de 2 × 10 ^ 4 radios de Schwarzschild de Sagitario A *.
- Analizó el perfil de la línea de emisión de doble pico y la distribución espacial para inferir las propiedades del gas.
Principales resultados:
- Se obtuvo con éxito una imagen de un disco de gas ionizado de 10^4 Kelvin girando alrededor de Sagitario A*.
- El disco exhibe una línea de emisión H30α de doble pico con un ancho de línea de velocidad total de ~ 2.200 km / s.
- La emisión observada es más fuerte de lo previsto, lo que sugiere una mejora del máser de la transición H30α.
Conclusiones:
- Las observaciones revelan un disco de gas giratorio con una masa estimada de 10^-5 a 10^-4 masas solares y una densidad de hidrógeno de 10^5 a 10^6 cm3.
- El desplazamiento espacial de los componentes de emisión desplazados al rojo y al azul indica la rotación dentro del disco.
- La emisión mejorada de H30α sugiere amplificación de maser, un hallazgo significativo para comprender la física de los gases cerca de los agujeros negros.
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