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Evidence for a Sudden Magnetic Field Reconfiguration in SGR 1900+14

Peter M. Woods·Chryssa Kouveliotou·Ersin Gogus·Mark H. Finger·Jean Swank·Don A. Smith·Kevin Hurley·Christopher Thompson
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Abstract

We report the detection of large flux changes in the persistent X-ray flux of SGR 1900+14 during its burst active episode in 1998. Most notably, we find a factor ~700 increase in the non-burst X-ray flux following the August 27th flare, which decayed in time as a power-law. Our measurements indicate that the pulse fraction remains constant throughout this decay. This suggests a global flux enhancement as a consequence of the August 27th flare rather than localized heating. While the persistent flux has since recovered to the pre-outburst level, the pulse profile has not. The pulse shape changed to a near sinusoidal profile within the tail of the August 27th flare (in gamma-rays) and this effect has persisted for more than 1.5 years (in X-rays). The results presented here suggest the magnetic field of the neutron star in SGR 1900+14 was significantly altered (perhaps globally) during the giant flare of August 27.

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Peter M. Woods, Chryssa Kouveliotou, Ersin Gogus, Mark H. Finger, Jean Swank, Don A. Smith, Kevin Hurley, Christopher Thompson. 2001-01-03. Evidence for a Sudden Magnetic Field Reconfiguration in SGR 1900+14. https://doi.org/10.1086/320571

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