Star forming activities in W75N and DR21 – Are the two regions in collision?

We have observed the massive star formation region W75N in 12CO J = 3 − 2 with KOSMA. The profile of 12CO J = 3 − 2 indicated that besides the 9 km s−1 component, there is another component of −3 km s−1, which is associated with another star formation region, DR21N, located to the north of DR21. We derived the physical and dynamical parameters of the core and high velocity gas associated with the two components separately. Star forming activities were investigated, including outflows and infall analysis. The two regions overlap in space and are not connected in velocity. We found that the cloud–cloud collision scenario may not apply for the DR21/W75N case.