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Swift and Chandra confirm the intensity-hardness correlation of the AXP 1RXS J170849.0-400910

S. Campana·N. Rea·G. L. Israel·R. Turolla·S. Zane
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Abstract

Convincing evidence for long-term variations in the emission properties of the anomalous X-ray pulsar 1RXS J170849.0-400910 has been gathered in the last few years. In particular, and following the pulsar glitches of 1999 and 2001, XMM-Newton witnessed in 2003 a decline of the X-ray flux accompanied by a definite spectral softening. This suggested the existence of a correlation between the luminosity and the spectral hardness in this source, similar to that seen in the soft gamma-repeater SGR 1806-20. Here we report on new Chandra and Swift observations of 1RXS J170849.0-400910 performed in 2004 and 2005, respectively. These observations confirm and strengthen the proposed correlation. The trend appears to have now reversed: the flux increased and the spectrum is now harder. The consequences of these observations for the twisted magnetosphere scenario for anomalous X-ray pulsars are briefly discussed.

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S. Campana, N. Rea, G. L. Israel, R. Turolla, S. Zane. 2006-11-07. Swift and Chandra confirm the intensity-hardness correlation of the AXP 1RXS J170849.0-400910. https://doi.org/10.1051/0004-6361%3A20065482

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