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Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
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El fondo cósmico de rayos gamma de la formación de estructuras en el medio intergaláctico.

Loeb1, Waxman

  • 1Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA. aloeb@cfa.harvard.edu

Nature
|May 23, 2000
PubMed
Resumen

La formación de la estructura cósmica genera electrones relativistas que dispersan los fotones de fondo cósmico de microondas, lo que explica el fondo difuso de rayos gamma. Este hallazgo se alinea con los modelos cosmológicos y las predicciones de la nucleosíntesis del Big Bang.

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Área de la Ciencia:

  • Cosmología Cosmología.
  • La astrofísica es la astrofísica.
  • Astrofísica de altas energías de alta energía.

Sus antecedentes:

  • El origen del fondo difuso de rayos gamma es un gran problema sin resolver en la cosmología.
  • Fuentes discretas como núcleos galácticos activos representan menos del 25% del flujo de rayos gamma observado.

Objetivo del estudio:

  • Para explicar el origen de la radiación de fondo difusa de rayos gamma.
  • Para vincular la formación de estructuras a gran escala con la emisión de rayos gamma.

Principales métodos:

  • Modelado de ondas de choque en el medio intergaláctico durante la formación de la estructura cósmica.
  • Simulando la dispersión de los fotones cósmicos de fondo de microondas por los electrones relativistas producidos por estos choques.

Principales resultados:

  • Las ondas de choque en el medio intergaláctico generan electrones altamente relativistas.
  • Estos electrones dispersan los fotones de fondo cósmico de microondas a las energías de rayos gamma, produciendo el fondo difuso.
  • El flujo predicho del modelo coincide con las observaciones a través de cuatro órdenes de magnitud en la energía del fotón.

Conclusiones:

  • El fondo difuso de rayos gamma se genera localmente por procesos de formación de estructuras cósmicas.
  • El modelo predice que el fondo de rayos gamma es isotrópico dentro del 5% en escalas angulares mayores de un grado.
  • El acuerdo implica una densidad media de bariones cosmológicos consistente con la nucleosíntesis del Big Bang.