Joint XMM-Newton comma Chandra comma and RXTE Observations of Dips in Cyg X-1

At orbital phase zero (i.e., the O star secondary intervening our line of sightto the black hole primary), Cyg X1 shows Xray dips due to highly variableabsorption in matter in the accretion stream. Studying the physics of these dipsrequires joint XMM/ChandraHETGS/RXTE observations: XMMNewton provides thecrucially important spectral continuum through the broad Fe line region at CCDresolution and it achieves high signaltonoise in the <2keV band, allowing thedipping events to be temporally resolved and spectrally modeled on short timescales. The simultaneous Chandra data provide high resolution spectroscopy ofthe dipping events (albeit at a lower time resolution compared to XMMNewton),while RXTE provides the hard Xray continuum out to >150keV. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]