On 2008 April 18/19 we observed Cygnus X-1 in a multi-satellite campaign encompassing XMM-Newton, Chandra, Suzaku, RXTE, Swift, and INTEGRAL as well as simultaneous coverage in the radio during orbital phase 0. The measurement represents the best broad-band spectrum of Cyg X-1 ever achieved. In this contribution we present first results from the analysis of the observation, focusing on the soft X-ray spectrum and the interaction of the black hole with the strong stellar wind of its donor star through absorption line studies.
talkIn 2005 February we observed Cygnus X-1 for a total of 10 days quasi-continuously with the Rossi X-ray Timing Explorerand the Ryle telescope. We present the results of the spectral and timing analysis on a timescale of 90 min and show that the behavior of Cyg X-1 is similar to that found during our years long monitoring campaign. As a highlight we present evidence for a full transition from the hard to the soft state that happened during less than three hours.
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