Kinematics and star formation toward W33: a central hub as a hub–filament system

We performed a large-scale mapping observation toward the W33 complex and its surroundings, covering an area of $1.3^\circ \times 1.0^\circ$ , in $^{12}$CO (1-0), $^{13}$CO C$^{18}$O (1-0) lines from Purple Mountain Observatory (PMO). found new hub--filament system ranging 30 to 38.5 \kms located at complex. Three supercritical filaments are directly converging into central hub W33. Velocity gradients detected along accretion rates order $\rm 10^{-3}\,M_\odot\, yr^{-1}$. The has total mass $\rm\sim 1.8\times10^5\,M_\odot$, accounting for $\sim 60\%$ system. This indicates that is reservoir hub-filament Furthermore, 49 ATLASGAL clumps associated with find $57\%$ be situated clustered intersections between Moreover, distribution Class I young stellar objects (YSOs) forms structure resembling peaks where group; it seems suggest mechanisms clump formation star this region correlated. Gas flows likely feed materials lead clustering might triggered by motion gas intersections.