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The pulse phase-dependent spectrum of the anomalous X-ray pulsar 1RXS J170849-400910

G. L. Israel·T. Oosterbroek·L. Stella·S. Campana·S. Mereghetti·A. N. Parmar
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Abstract

We report on the results of a 50ks BeppoSAX observation of 1RXS J170849-400910, one of the five (plus a candidate) known anomalous X-ray pulsars. The BeppoSAX data are consistent with a power-law plus blackbody spectral decomposition, making 1RXS J170849-400910 the fourth source of this class for which such a spectral decomposition was found. The inferred power-law slope and blackbody temperature are Gamma~2.6 and kT_BB~0.46keV, respectively. We found significant energy-dependence of the pulse profile, a remarkable feature for an AXP. By using the power-law plus blackbody decomposition we detected a significant variation in at least one spectral parameter, the power-law photon index, as a function of the pulse phase. This is the first significant detection of spectral parameter variation in an AXP. The implications of these results are briefly discussed.

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G. L. Israel, T. Oosterbroek, L. Stella, S. Campana, S. Mereghetti, A. N. Parmar. 2001-08-31. The pulse phase-dependent spectrum of the anomalous X-ray pulsar 1RXS J170849-400910. https://doi.org/10.1086/324169

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