Jet interaction of SS 433 with the ambient medium

SS 433 is a bright X-ray binary with two sided jets moving at 0.26 c. It is located at the center of the supernova remnant W50, suggesting that SS 433 is associated with W50. A large molecular cloud also surrounds the SS 433/W50 system. Recent observations with ROSAT and ASCA have shown X-ray hot spots interpreted as SS 433 jets interacting with the ambient interstellar medium. To verify this hypothesis, we have performed observations of the molecular cloud around SS 433 in the J=1−0 and J=2−1 lines of CO transitions along and perpendicular to the jet axis and have found two clouds with velocities of 32 km/s and 50 km/s respectively. Due to a strong correlation between the 50 km/s map and the X-ray hot spots, we conclude that SS 433 is inside or at the edge of the 50 km/s molecular cloud.