Cloud–Cloud Collision and Cluster Formation in the W5-NW Complex

Abstract

We present a detailed structural and gas kinematic study of the star-forming complex W5-NW. A cloud–cloud collision scenario unravels with evidence of collision-induced star and cluster formation. Various signatures of cloud–cloud collision such as “complementary distribution” and “bridging features” are explored. At the colliding region, the two clouds have complementary morphologies, where W5-NWb has a filamentary key-like shape that fits into the U-shaped cavity in W5-NWa that behaves like a keyhole. The interaction region between the two clouds is characterized by bridging features with intermediate velocities connecting the two clouds. A skewed V-shaped bridging feature is also detected at the site of the collision. A robust picture of the molecular gas distribution highlighting the bridges is seen in the position–position–velocity diagram obtained using the SCOUSEPY algorithm. Star cluster formation with an overdensity of Class I and Class II young stellar objects is also seen towards this cloud complex, likely triggered by the cloud collision event.