A spectral study of the X-ray pulsar 4U 0115+63

Presentation duration: 15 minutes

Presenter: Sebastian Müller

We present the preliminary results of the spectral analysis of the 2008 outburst of the High Mass X-ray binary 4U 0115+63, recorded by RXTE and INTEGRAL. To date, literature claims the centroid energy of the cyclotron resonance scattering feature of 4U 0115+63 to be anti-correlated to its X-ray flux. We find a basically different flux-dependend behavior of this feature, based on the choice of the X-ray continuum model. This result comes along with strong impacts on the theoretical understanding of accreting X-ray pulsars.