1996A&A...312..306B

SS 433 and the surrounding supernova remnant W 50 were observed in several pointings between March 1991 and March 1993 with the PSPC onboard ROSAT for a total of more than 60ksec. The soft X-ray flux from SS 433 varies by up to a factor of two but no clear correlation could be found with precessional or binary phase. The temperature of the best fit thermal spectrum cannot be constrained accurately, but kT>2keV. The N_H value towards SS 433 itself seems to be higher than to the rest of the remnant. The two oppositely directed X-ray jets show different morphological and spectral properties indicating a strong influence of the surrounding matter onto the energy loss mechanism of the jet. The spectrum of the eastern jet is non-thermal with a power law photon index {GAMMA}∼1.6. The jet terminates in a region with thermal emission with strong spatial similarities between the X-ray and the radio structures. The western jet has a considerably softer X-ray spectrum, either of thermal origin or with a steep power law ( {GAMMA}>2.3).