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   71061
   The galactic jet source SS 433 has two non-thermal X-ray lobes, which
   are considered to be produced by the collision of the relativistic jets
   with the surrounding SNR W50. The same collision is expected to produce
   hot plasma in the front shock region out in the shell, but little
   evidence has been known. ASCA accidentally observed a part of the W50
   shell near the end of the non-thermal lobe, where we detected weak
   thermal X-ray emission. The data, however, is poor in statistics with
   only 10 ks exposure. Here we propose to observe 3 positions on the W50
   shell to investigate the interaction of the jet with the shell: two
   positions outside the X-ray lobes where the jet collides the shell, and
   another position where the original SNR shell is preserved free from
   the jet interaction.
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