An unusual burst from soft gamma repeater SGR 1900+ 14: comparisons with giant flares and implications for the magnetar model

Abstract:

The soft gamma-ray repeater SGR 1900+ 14 entered a remarkable phase of activity during the summer of 1998. This activity peaked on 1998 August 27, when a giant periodic γ-ray flare resembling the famous 1979 March 5 event from SGR 0526-66 was recorded. Two days later (August 29), a strong, bright burst was detected simultaneously with the Rossi X-Ray Timing Explorer (RXTE) and the Burst and Transient Source Experiment (BATSE). This event reveals several similarities to the giant flares of August 27 and March 5 and shows a number of unique features not previously seen in SGR bursts. Unlike typically short SGR bursts (duration∼ 0.1 s), this event exhibits a 3.5 s burst peak that was preceded by an extended (∼ 1 s) complex precursor, and followed by a long (∼ 10 3 s) pulsating tail modulated at the 5.16 s stellar rotation period. Spectral analysis shows a striking distinction between the spectral …

Año de publicación:

2001

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