THE X-RAY-EMISSION OF SS-433

Recent X-ray observations of SS 433 with the Ginga satellite, centered at the phases of optical primary minimum revealed new information about the systems properties. The main observational result is that the spectrum of the source is extremely hard, best fitted with a thermal bremsstrahlung law with kT less-than-or-similar-to 30 keV, which softens during eclipse to kT almost-equal-to 12 keV. The 6.7 keV iron line region appears to be very complex and varies with the processional phase. It is argued that the X-ray flux from the jets is strongly modulated by large structures on the disc. If these can be modelled properly they will provide important clues to the disc's physical properties which might lead to a better understanding of the precession mechanism.