Investigating Embedded Structures and Gas Kinematics in the Infrared-dark Cloud Hosting Bubble N59-North

Abstract We present a multiwavelength study of an extended area hosting the bubble N59-North to explore the physical processes driving massive star formation (MSF). The Spitzer 8 μ m image reveals an elongated/filamentary infrared-dark cloud (length ∼28 pc) associated with N59-North, which contains several protostars and seven ATLASGAL dust clumps at the same distance. The existence of this filament is confirmed through 13 CO and NH 3 molecular line data in a velocity range of [95, 106] km s −1 . All dust clumps satisfy Kauffmann and Pillai’s condition for MSF. Using Spitzer 8 μ m image, a new embedded hub-filament system candidate (C-HFS) is investigated toward the ATLASGAL clump, located near the filament’s central region. MeerKAT 1.3 GHz continuum emission, detected for the first time toward C-HFS, reveals an ultracompact H ii region driven by a B2-type star, suggesting an early stage of HFS with minimal feedback from the young massive star. The comparison of the position–velocity (PV) and position-PV (PPV) diagrams with existing theoretical models suggests that rotation, central collapse, and end-dominated collapse are not responsible for the observed gas motion in the filament. The PPV diagram indicates the expansion of N59-North by revealing blueshifted and redshifted gas velocities at the edge of the bubble. Based on comparisons with magnetohydrodynamic simulations, this study suggests that cloud–cloud collision (CCC) led to the formation of the filament, likely giving it a conical structure with gas converging toward its central region, where C-HFS is located. Overall, the study supports multi-scale filamentary mass accretion for MSF, likely triggered by CCC.