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arXiv · 1710.05150

Inversion of the decay of the cyclotron line energy in Her X-1

R. Staubert·D. Klochkov·F. Fürst·J. Wilms·R. E. Rothschild·F. Harrison
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Abstract

Recent observations of Her X-1 with NuSTAR and INTEGRAL in 2016 have provided evidence that the 20-year decay of the cyclotron line energy found between 1996 and 2015 has ended and that an inversion with a new increase, possibly similar to the one observed around 1990-1993, has started. We consider this a strong motivation for further observations and for enhanced efforts to significantly improve our theoretical understanding of the accretion process in binary X-ray pulsars. We speculate about the physics behind the long-term decay and its inversion, a possible cyclic behavior, and correlations with other variable observables.

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R. Staubert, D. Klochkov, F. Fürst, J. Wilms, R. E. Rothschild, F. Harrison. 2017-10-14. Inversion of the decay of the cyclotron line energy in Her X-1. https://doi.org/10.1051/0004-6361%2F201731927

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