[AGN, Quasars, Black Holes -- Oral ]

Spectroscopy of the photoionized wind and absorption dips in the Cyg X-1 system

Manfred Hanke, University of Erlangen-Nuremberg
Jörn Wilms (University of Erlangen-Nuremberg), Michael A. Nowak (MKI-CXC), Katja Pottschmidt (NASA-GSFC), Norbert S. Schulz (MKI-CXC), Julia C. Lee (SAO)

We present results from our simultaneous observations of the high-mass X-ray binary system Cygnus X-1 / HDE 226868 with Chandra-HETGS, XMM-Newton, Suzaku, RXTE, INTEGRAL, and Swift in 2008 April. The observations have been performed shortly after phase 0 of the 5.6 d orbit when our line of sight to the accreting black hole passes through the densest part of the wind of the donor star.In the context of a consistent description for the 0.5--600 keV spectrum, the high resolution gratings spectra allow us to study the composition and dynamics of the highly photoionized wind. Dense structures in this clumpy O-star wind lead to transient absorption dips in the soft X-ray band. A color-color diagram shows evidence that the additional absorber causing the dips only covers part of the X-ray emitting region. The spectroscopic analysis reveals changes in the ionization state of the wind material between dip and non-dip phases.