We report an observational study of the giant molecular cloud ( GMC ) associated with the Galactic infrared ring-like structure N35 and two nearby H ii regions G024.392+00.072 ( H ii region A ) and G024.510-00.060 ( H ii region B ) , using the new CO J =1–0 data obtained as a part of the FOREST Unbiased Galactic Plane Imaging survey with the Nobeyama 45-m telescope ( FUGIN ) project at a spatial resolution of 21 ^ { \prime \prime } .
Our CO data revealed that the GMC , with a total molecular mass of 2.1 \times 10 ^ { 6 } M _ { \odot } , has two velocity components over \sim 10–15 km s ^ { -1 } .
The majority of molecular gas in the GMC is included in the lower-velocity component ( LVC ) at \sim 110–114 km s ^ { -1 } , while the higher-velocity components ( HVCs ) at \sim 118–126 km s ^ { -1 } consist of three smaller molecular clouds which are located near the three H ii regions .
The LVC and HVCs show spatially complementary distributions along the line-of-sight , despite large velocity separations of \sim 5–15 km s ^ { -1 } , and are connected in velocity by the CO emission with intermediate intensities .
By comparing the observations with simulations , we discuss a scenario where collisions of the three HVCs with LVC at velocities of \sim 10–15 km s ^ { -1 } can provide an interpretation of these two observational signatures .
The intermediate velocity features between the LVC and HVCs can be understood as broad bridge features , which indicate the turbulent motion of the gas at the collision interfaces , while the spatially complementary distributions represent the cavities created in the LVC by the HVCs through the collisions .
Our model indicates that the three H ii regions were formed after the onset of the collisions , and it is therefore suggested that the high-mass star formation in the GMC was triggered by the collisions .