From filaments to the hub: Gas kinematics and massive star formation in G329.34+0.14

We present 13 CO (J=2–1) emission from the SEDIGISM survey, together with ALMA Band 3 and Band 6 observations from the ATOMS and QUARKS surveys, to investigate the gas kinematics and feedback processes in the massive hub-filament system G329.34+0.14 (hereafter G329). Based on Herschel continuum morphology together with the 13 CO (J=2–1) integrated intensity and velocity distributions, a parsec-scale network of filaments was identified, converging toward the hub that hosts two massive clumps, MC 1 and MC 2, with respective masses of ~4210 (±1259) M ⊙ and ~1483 (±443) M ⊙ . Position-velocity analysis reveals systematic projected velocity gradients along the filaments, consistent with organized gas motions on parsec scales and possible inflows toward the hub. Within MC 1, ALMA resolves a sub-parsec network of intra-hub filaments (IHFs) traced by H 13 CO + (J=1–0), with a velocity organization similar to that seen on parsec scales. These IHFs are distributed around a central H II region, surrounded by a shell-like structure traced by CS (J=2–1) and H 13 CO + (J=1–0) emission, with dense gas concentrated in its northeastern and southwestern sectors. The shell further shows SiO (J=2–1) and SO (J=3(2)–2(1)) emission, excited mainly by low-velocity shocks from the expansion of the H II region, with a minor contribution from protostellar outflows. Compared with the surrounding parsec-scale filaments, the IHFs are more compact but exhibit larger velocity gradients and line masses, suggesting that the inner hub gas is denser and dynamically more complex. MC 1 and MC 2 are interpreted as two massive clumps embedded in the same hub, with MC 1 appearing more evolved and more strongly affected by feedback than MC 2. G329 therefore provides an observational case in which the parsec-scale hub-filament structure and the dense IHF network show a broadly similar velocity organization. This suggests a possible kinematic connection between the surrounding filaments and dense gas in the hub interior.