出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray
state of CygnusX-1 is correlated with the properties of the wind which defines the environment of
mass accretion. Chandra-HETGS observations close to orbital phase 0 allow for an analysis of the
photoionzed stellar wind at high resolution, but because of the strong variability due to soft X-ray
absorption dips, simultaneous multi-satellite observations are required to track and understand
the continuum, too. Besides an earlier joint Chandra and RXTE observation, we present first
results from a recent campaign which represents the best broad-band spectrum of CygX-1 ever
achieved: On 2008 April 18/19 we observed this source with XMM-Newton, Chandra, Suzaku,
RXTE, INTEGRAL, Swift, and AGILE in X- and g -rays, as well as with VLA in the radio.
After superior conjunction of the black hole, we detect soft X-ray absorption dips likely due to
clumps in the focused wind covering ≥ 95% of the X-ray source, with column densities likely to
be of several 1023 cm−2, which also affect photon energies above 20 keV via Compton scattering.
