Revealing the broad iron Kalpha line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations

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We report on the analysis of the broad Fe Kalpha line feature of Cygnus X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL).

• The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kalpha reflection line at 6.4keV with a very high signal to noise ratio.
• The 4-500keV energy range is used to constrain the underlying continuum and the reflection at higher energies.
• We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection.