An exceptionally bright flare from SGR 1806-20 and the origins of short-duration gamma-ray bursts.
Nature
; 434(7037): 1098-103, 2005 Apr 28.
Article
en En
| MEDLINE
| ID: mdl-15858565
ABSTRACT
Soft-gamma-ray repeaters (SGRs) are galactic X-ray stars that emit numerous short-duration (about 0.1 s) bursts of hard X-rays during sporadic active periods. They are thought to be magnetars strongly magnetized neutron stars with emissions powered by the dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR 1806-20, which was much more luminous than any previous transient event observed in our Galaxy. (In the first 0.2 s, the flare released as much energy as the Sun radiates in a quarter of a million years.) Its power can be explained by a catastrophic instability involving global crust failure and magnetic reconnection on a magnetar, with possible large-scale untwisting of magnetic field lines outside the star. From a great distance this event would appear to be a short-duration, hard-spectrum cosmic gamma-ray burst. At least a significant fraction of the mysterious short-duration gamma-ray bursts may therefore come from extragalactic magnetars.
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Base de datos:
MEDLINE
Idioma:
En
Revista:
Nature
Año:
2005
Tipo del documento:
Article
País de afiliación:
Estados Unidos