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arXiv · 1209.1918

The reawakening of the sleeping X-ray pulsar XTE J1946+274

Sebastian Müller·Matthias Kühnel·Isabel Caballero·Katja Pottschmidt·Felix Fürst·Ingo Kreykenbohm·Macarena Sagredo·Maria Obst·Jörn Wilms·Carlo Ferrigno·Richard E. Rothschild·Rüdiger Staubert
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Abstract

We report on a series of outbursts of the high mass X-ray binary XTE J1946+274 in 2010/2011 as observed with INTEGRAL, RXTE, and Swift. We discuss possible mechanisms resulting in the extraordinary outburst behavior of this source. The X-ray spectra can be described by standard phenomenological models, enhanced by an absorption feature of unknown origin at about 10 keV and a narrow iron K alpha fluorescence line at 6.4 keV, which are variable in flux and pulse phase. We find possible evidence for the presence of a cyclotron resonance scattering feature at about 25 keV at the 93% level. The presence of a strong cyclotron line at 35 keV seen in data from the source's 1998 outburst and confirmed by a reanalysis of these data can be excluded. This result indicates that the cyclotron line feature in XTE J1946+274 is variable between individual outbursts.

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Sebastian Müller, Matthias Kühnel, Isabel Caballero, Katja Pottschmidt, Felix Fürst, Ingo Kreykenbohm, Macarena Sagredo, Maria Obst, Jörn Wilms, Carlo Ferrigno, Richard E. Rothschild, Rüdiger Staubert. 2012-09-10. The reawakening of the sleeping X-ray pulsar XTE J1946+274. https://doi.org/10.1051/0004-6361/201219580

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