Investigating the Globally Collapsing Hub-Filament Cloud G326.611+0.811
He Y.-X. Liu H.-L. Tang X.-D. Qin S.-L. Zhou J.-J. Esimbek J. Pan S.-R. Li D.-L. Zhao M.-K. Ji W.-G. Komesh T.
1 November 2023Institute of Physics
Astrophysical Journal
2023#957Issue 2
We present a dynamics study toward the G326.611+0.811 (G326) hub-filament system (HFS) cloud using new APEX observations of both 13CO and C18O (J = 2-1). The G326 HFS cloud constitutes a central hub and at least four hub-composing filaments that are divided into a major branch of filaments (F1 and F2) and a side branch (F3-F5). The cloud holds ongoing high-mass star formation as characterized by three massive dense clumps (i.e., 370-1100 M ⊙ and 0.14-0.16 g cm−2 for C1-C3) with high clump-averaged mass infalling rates (>10−3 M ⊙ yr−1) within the major filament branch, and the associated point sources bright at 70 μm, typical of young protostars. Along the five filaments, velocity gradients are found in both 13CO and C18O (J = 2-1) emission, suggesting that filament-aligned gravitational collapse toward the central hub (i.e., C2) is responsible for the high-mass star formation therein. Moreover, a periodic velocity oscillation along the major filament branch is revealed in both 13CO and C18O (J = 2-1) emission with a characteristic wavelength of ∼3.5 pc and an amplitude of ∼0.31-0.38 km s−1. We suggest that this pattern of velocity oscillation in G326 could arise from clump-forming gas motion induced by gravitational instabilities. The prevalent velocity gradients, fragmentation of the major branch of filaments, and the ongoing collapse of the three massive dense clumps are indicative that G326 is an HFS undergoing global collapse.
Text of the article Перейти на текст статьи
Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, 830011, China
Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing, 210008, China
Xinjiang Key Laboratory of Radio Astrophysics, Urumqi, 830011, China
School of Physics and Astronomy, Yunnan University, Kunming, 650091, China
University of Chinese Academy of Sciences, Beijing, 100049, China
Energetic Cosmos Laboratory, Nazarbayev University, Nur-Sultan, 010000, Kazakhstan
Faculty of Physics and Technology, Al-Farabi Kazakh National University, Almaty, 050040, Kazakhstan
Xinjiang Astronomical Observatory
Key Laboratory of Radio Astronomy
Xinjiang Key Laboratory of Radio Astrophysics
School of Physics and Astronomy
University of Chinese Academy of Sciences
Energetic Cosmos Laboratory
Faculty of Physics and Technology
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026