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Desintegración del resplandor óptico del GRB 990123: implicaciones para el modelo de bola de fuego
A J Castro-Tirado1, M R Zapatero-Osorio, N Caon
1Instituto de Astrofisica de Andalucia, IAA-CSIC, Granada, Spain. Instituto de Astrofisica de Canarias, La Laguna, Tenerife, Spain. Astronomical Observatory, University of Copenhagen, Copenhagen, Denmark. Nordic Optical Telescope, La Palma, T.
Science (New York, N.Y.)
|March 26, 1999
Resumen
Las observaciones de la explosión de rayos gamma GRB 990123 revelan una curva de luz en declive suave. La evidencia sugiere que un chorro colimado puede ser responsable de la tasa de declive más pronunciada observada después del evento.
Área de la Ciencia:
- * Astrofísica es la astrofísica.
- * Astrofísica de alta energía.
- * Cosmología observacional.
Sus antecedentes:
- * Las explosiones de rayos gamma (GRB) son los eventos electromagnéticos más luminosos en el universo.
- * Comprender los mecanismos de emisión de GRB y los sistemas progenitor es crucial para la astrofísica.
- * GRB 990123 fue un evento excepcionalmente brillante, proporcionando una oportunidad única para un estudio detallado.
Objetivo del estudio:
- * Para analizar el resplandor de banda ancha de GRB 990123.3.
- * Para investigar la evolución temporal y espectral del GRB 990123 afterglow.
- * Para restringir los modelos de emisión y sondear la naturaleza del chorro GRB.
Principales métodos:
- * Se realizaron observaciones de banda ancha desde el ultravioleta hasta el infrarrojo cercano, comenzando 8,5 horas después del evento.
- * Utilizados datos del Telescopio Robótico y Experimento de Fuentes Transientes (ROTSE) y el Telescopio Espacial Hubble (HST).
- * Analizó la curva de luz para las tasas de decaimiento temporal y la evolución del color.
Principales resultados:
- * Se observó una curva de luz suavemente decreciente en el resplandor posterior del GRB 990123.3.
- * Se identificó una dependencia de color posiblemente relacionada con una ruptura de enfriamiento en la banda óptica ultravioleta alrededor de 1 día después del evento.
- * Se detectó una tasa de disminución más pronunciada después de 1.5 a 2 días, indicativa de colimación de chorro.
Conclusiones:
- * La curva de luz de resplandor de GRB 990123 es consistente con la emisión de una bola de fuego en expansión suave.
- * La interrupción de enfriamiento observada sugiere una transición en el mecanismo de emisión o enfriamiento de partículas.
- * La decadencia más pronunciada apunta hacia una estructura de chorro relativista y colimada dirigida hacia el observador.
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