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Detección de rayos gamma pulsados por encima de 100 GeV desde el pulsar del Cangrejo
1Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027, USA.
Science (New York, N.Y.)
|October 8, 2011
Resumen
Los rayos gamma de alta energía detectados desde el púlsar del Cangrejo desafían los modelos actuales. Estas partículas energéticas se originan lejos de la estrella de neutrones, lo que requiere nuevas explicaciones para los mecanismos de emisión de pulsares.
Área de la Ciencia:
- Astrofísica de altas energías de alta energía.
- La física del púlsar es la física del púlsar.
- La astronomía de rayos gamma es una astronomía de rayos gamma.
Sus antecedentes:
- El púlsar del Cangrejo es una estrella de neutrones bien estudiada que emite a través del espectro electromagnético.
- Las observaciones anteriores del púlsar del Cangrejo en rayos gamma se han limitado a energías más bajas.
- Comprender la aceleración de partículas y los mecanismos de emisión en los púlsares es un desafío clave en la astrofísica.
Objetivo del estudio:
- Para informar sobre la detección de rayos gamma pulsados del púlsar Crab a energías altas sin precedentes.
- Para investigar las propiedades espectrales de esta emisión de alta energía.
- Para limitar los modelos teóricos de la aceleración de partículas y la producción de rayos gamma en púlsares.
Principales métodos:
- Utilizó el Sistema de Array de Telescopio de Imágenes de Radiación Muy Energética (VERITAS), una serie de telescopios atmosféricos Cherenkov.
- Analizaron las señales de luz de Cherenkov para reconstruir los eventos de rayos gamma.
- Se realizó un análisis espectral de la emisión pulsada del púlsar Crab.
Principales resultados:
- Se detectaron pulsos de rayos gamma del púlsar Crab con energías superiores a 100 gigaelectronvoltios (GeV).
- El espectro de fotones de la emisión pulsada entre 100 megaelectronvoltios y 400 GeV se describe mejor con una ley de potencia rota.
- Es poco probable que los rayos gamma de alta energía observados se originen en la radiación de curvatura y sugieren un sitio de producción más allá de 10 radios estelares de la estrella de neutrones.
Conclusiones:
- La detección de rayos gamma pulsados >100 GeV del púlsar del Cangrejo es inconsistente con los modelos actuales de emisión de púlsares.
- El espectro observado y la región de emisión inferida requieren revisiones de las teorías de aceleración de partículas y radiación en púlsares.
- El trabajo teórico futuro debe tener en cuenta estas observaciones de alta energía, que potencialmente implican mecanismos que operan a mayores distancias de la estrella de neutrones.
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