Observations of the Line Profiles of H2 in the DR 21 Molecular Cloud

The profile of the H₂ υ = 1-0 S(1) emission line in the molecular cloud associated with the DR 21 H II region has been observed at the positions of three of the H₂ emission peaks. In all cases, the H₂ line is blueshifted with respect to the velocity of the surrounding molecular cloud. This asymmetry is more pronounced in the west lobe, where velocities up to -80 km s^-1 with respect to the ambient cloud are detected. The line profiles appear to be caused by the collision with the ambient cloud of a high-velocity molecular outflow originating at or near the position of the H₂O maser.