학술논문
ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- XI. From inflow to infall in hub-filament systems
Document Type
Working Paper
Author
Zhou, Jian-Wen; Liu, Tie; Evans II, Neal J.; Garay, Guido; Goldsmith, Paul F.; Gomez, Gilberto C.; Vazquez-Semadeni, Enrique; Liu, Hong-Li; Stutz, Amelia M.; Wang, Ke; Juvela, Mika; He, Jinhua; Li, Di; Bronfman, Leonardo; Liu, Xunchuan; Xu, Feng-Wei; Tej, Anandmayee; Dewangan, L. K.; Li, Shanghuo; Zhang, Siju; Zhang, Chao; Ren, Zhiyuan; Tatematsu, Kenichi; Li, Pak Shing; Lee, Chang Won; Baug, Tapas; Qin, Sheng-Li; Wu, Yuefang; Peng, Yaping; Zhang, Yong; Liu, Rong; Luo, Qiu-Yi; Ge, Jixing; Saha, Anindya; Chakali, Eswaraiah; zhang, Qizhou; Kim, Kee-Tae; Ristorcelli, Isabelle; Shen, Zhi-Qiang; Li, Jin-Zeng
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Abstract
We investigate the presence of hub-filament systems in a large sample of 146 active proto-clusters, using H$^{13}$CO$^{+}$ J=1-0 molecular line data obtained from the ATOMS survey. We find that filaments are ubiquitous in proto-clusters, and hub-filament systems are very common from dense core scales ($\sim$0.1 pc) to clump/cloud scales ($\sim$1-10 pc). The proportion of proto-clusters containing hub-filament systems decreases with increasing dust temperature ($T_d$) and luminosity-to-mass ratios ($L/M$) of clumps, indicating that stellar feedback from H{\sc ii} regions gradually destroys the hub-filament systems as proto-clusters evolve. Clear velocity gradients are seen along the longest filaments with a mean velocity gradient of 8.71 km s$^{-1}$pc$^{-1}$ and a median velocity gradient of 5.54 km s$^{-1}$pc$^{-1}$. We find that velocity gradients are small for filament lengths larger than $\sim$1~pc, probably hinting at the existence of inertial inflows, although we cannot determine whether the latter are driven by large-scale turbulence or large-scale gravitational contraction. In contrast, velocity gradients below $\sim$1~pc dramatically increase as filament lengths decrease, indicating that the gravity of the hubs or cores starts to dominate gas infall at small scales. We suggest that self-similar hub-filament systems and filamentary accretion at all scales may play a key role in high-mass star formation.
Comment: 16 pages
Comment: 16 pages