X-ray lobes of W 50/SS 433 system

The X-ray lobes (ie on both sides feast and west) of SS 433, and are presum ably produced by the interaction of the jets of SS 433 with the surrounding SNR W 50. The non-thermal nature of the east lobe has been reported by Yam auchi et al. (1994) using ASCA data. With the further ASCA observations, we studied the spectra and morphology of both the east and nest lobes in deta il. Their spectra have no emission lines, and are well described by power-l am models with interstellar absorption. The X-ray emission becomes softer o n both sides with increasing distance from SS 433. The X-ray surface bright ness peaks closer to SS 433 in the high-energy band than in the low energy band, suggesting that the high energy electrons in the X-ray lobes lose ene rgies by synchrotron emission as they travel away from SS 433. We estimate the magnetic field and the total energy of the high energy electrons to be similar to 2 mu G and similar to 5 x 10(46) erg, respectively.