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arXiv · 0704.1630

Exciting the Magnetosphere of the Magnetar CXOU J164710.2-455216 in Westerlund 1

M. P. Muno·B. M. Gaensler·J. S. Clark·R. de Grijs·D. Pooley·I. R. Stevens·S. F. Portegies Zwart
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Abstract

We describe XMM-Newton observations taken 4.3 days prior to and 1.5 days subsequent to two remarkable events that were detected with Swift on 2006 September 21 from the candidate magnetar CXOU J164710.2-455216: (1) a 20 ms burst with an energy of 1e37 erg (15-150 keV), and (2) a rapid spin-down (glitch) with a fractionap period change of 1e-4. We find that the luminosity of the pulsar increased by a factor of 100 in the interval between observations, from 1e33 to 1e35 erg/s (0.5-8.0 keV), and that its spectrum hardened. The pulsed count rate increased by a factor of 10 (0.5-8.0 keV), but the fractional rms amplitude of the pulses decreased from 65 to 11 per cent, and their profile changed from being single-peaked to exhibiting three peaks. Similar changes have been observed from other magnetars in response to outbursts, such as that of 1E 2259+586 in 2002 June. We suggest that a plastic deformation of the neutron star's crust induced a very slight twist in the external magnetic field, which in turn generated currents in the magnetosphere that were the direct cause of the X-ray outburst.

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M. P. Muno, B. M. Gaensler, J. S. Clark, R. de Grijs, D. Pooley, I. R. Stevens, S. F. Portegies Zwart. 2007-04-12. Exciting the Magnetosphere of the Magnetar CXOU J164710.2-455216 in Westerlund 1. https://doi.org/10.1111/j.1745-3933.2007.00317.x

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