4U 0115+63: A Bonanza of Cyclotron Resonance Scattering Features

Date

2011

Type of Work

Department

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Citation of Original Publication

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Abstract

We report on an outburst of the high mass X-ray binary 4U 0115+634 with a pulse period of 3.6 s in 2008 as observed with INTEGRAL and RXTE. By analysing the lightcurves we derived an updated orbital period of the binary system. We also studied the pulse profile variations as a function of time and energy. We find evidence for phase lags at ∼11 and ∼22 keV. In our spectral analysis we found clear evidence for at least two cyclotron features. The continuum can be described by two different models, which lead to a fundamental difference in the behavior of the cyclotron features. We discuss possible reasons for this disagreement.