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arXiv · 2212.02627

Formation of hub-filament structure triggered by cloud-cloud collision in W33 complex

Jian-Wen Zhou·Shanghuo Li·Hong-Li Liu·Yaping Peng·Siju Zhang·Feng-Wei Xu·Chao Zhang·Tie Liu·Jin-Zeng Li
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Abstract

Hub-filament systems are suggested to be birth cradles of high-mass stars and clusters, but the formation of hub-filament structure is still unclear. Using the survey data FUGIN $^{13}$CO (1-0), C$^{18}$O (1-0), and SEDIGISM $^{13}$CO (2-1), we investigate formation of hub-filament structure in W33 complex. W33 complex consists of two colliding clouds, called W33-blue and W33-red. We decompose the velocity structures in W33-blue by fitting multiple velocity components, and find a continuous and monotonic velocity field. Virial parameters of Dendrogram structures suggest the dominance of gravity in W33-blue. The strong positive correlation between velocity dispersion and column density indicates the non-thermal motions in W33-blue may originate from gravitationally driven collapse. These signatures suggest that the filamentary structures in W33-blue result from the gravitational collapse of the compressed layer. However, the large scale velocity gradient in W33-blue may mainly originate from the cloud-cloud collision and feedback of active star formation, instead of the filament-rooted longitudinal inflow. From the above observed results, we argue that the cloud-cloud collision triggers formation of hub-filament structures in W33 complex. Meanwhile, the appearance of multiple-scale hub-filament structures in W33-blue is likely an imprint of the transition from the compressed layer to a hub-filament system.

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Jian-Wen Zhou, Shanghuo Li, Hong-Li Liu, Yaping Peng, Siju Zhang, Feng-Wei Xu, Chao Zhang, Tie Liu, Jin-Zeng Li. 2022-12-05. Formation of hub-filament structure triggered by cloud-cloud collision in W33 complex. https://doi.org/10.1093/mnras%2Fstac3559

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