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arXiv · astro-ph/9712023

BeppoSAX observations of the X-ray binary pulsar 4U1626-67

M. Orlandini·D. Dal Fiume·F. Frontera·S. Del Sordo·S. Piraino·A. Santangelo·A. Segreto·T. Oosterbroek·A. N. Parmar
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Abstract

We report on observations of the low-mass X-ray binary 4U1626-67 performed during the BeppoSAX Science Verification Phase. We present the broad-band 0.1-100 keV pulse averaged spectrum, that is well fit by a two-component function: a 0.27 +/- 0.02 keV blackbody and an absorbed power law with a photon index of 0.89 +/- 0.02. A very deep and narrow absorption feature at 38 keV, attributable to electron cyclotron resonance, is clearly visible in the broad-band spectrum. It corresponds to a neutron star magnetic field strength of 3.3 x 10^{12} G. The 4U1626-67 pulse profiles show a dramatic dependance on energy: the transition between the low energy (E<10 keV) "bi-horned" shape to the high-energy (E>10 keV) sinusoidal profile is clearly visible in our data. The modulation index shows a monotonic increase with energy.

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M. Orlandini, D. Dal Fiume, F. Frontera, S. Del Sordo, S. Piraino, A. Santangelo, A. Segreto, T. Oosterbroek, A. N. Parmar. 1997-12-02. BeppoSAX observations of the X-ray binary pulsar 4U1626-67. https://doi.org/10.1016/s0920-5632(98)00200-x

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