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Detección de Fermi de un luminoso púlsar de rayos γ en un cúmulo globular
Science (New York, N.Y.)
|November 5, 2011
Resumen
El telescopio Fermi detectó pulsaciones de rayos gamma de alta energía del púlsar J1823-3021A en NGC 6624. Este púlsar de milisegundos (MSP, por sus siglas en inglés) exhibe una luminosidad récord, lo que lo sugiere.
Área de la Ciencia:
- * Astrofísica de alta energía.
- * Astronomía de rayos gamma en el espacio.
- * Física de los púlsares.
Sus antecedentes:
- * Los cúmulos globulares son sistemas estelares densos que contienen pulsares.
- * Los púlsares de milisegundos (MSP) son estrellas de neutrones que giran rápidamente.
- * Las estimaciones anteriores sugirieron ~ 100 MSP de rayos gamma en NGC 6624.
Objetivo del estudio:
- * Informar de la detección de pulsaciones de rayos gamma de J1823-3021A utilizando el Telescopio de Gran Área Fermi.
- * Para caracterizar las propiedades de este púlsar y su contribución a la emisión del cúmulo.
- * Reevaluar la población de MSP en grupos globulares basado en nuevas observaciones.
Principales métodos:
- * Se utilizaron datos del Telescopio de Gran Área Fermi para detectar pulsaciones de rayos gamma (>100 MeV).
- * El púlsar analizado J1823-3021A y su cúmulo globular anfitrión NGC 6624.
- * Calculó la luminosidad de rayos gamma y la comparó con las propiedades conocidas de MSP.
Principales resultados:
- * Detección significativa (~7 σ) de las pulsaciones de rayos gamma de J1823-3021A.
- * Se observó una luminosidad de rayos gamma récord para una MSP (8.4 ± 1.6 × 10^34 ergs/s), dominando la emisión del cúmulo.
- * Restringido el número de MSP de rayos gamma en NGC 6624 a <32, revisando las estimaciones anteriores.
Conclusiones:
- * La alta luminosidad sugiere que el spin-down de J1823-3021A es intrínseco, lo que indica un gran campo magnético y una edad temprana para una MSP.
- * Las MSP anómalas como J1823-3021A pueden formarse a tasas comparables a las MSP normales.
- * Revisa la comprensión de las poblaciones de MSP en grupos globulares y sus mecanismos de formación.
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