ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions – V. Hierarchical fragmentation and gas dynamics in IRDC G034.43+00.24. Issue 4 (11th November 2021)

• Record Type: Journal Article
• Authors: Liu, Hong-Li; Tej, Anandmayee; Liu, Tie; Issac, Namitha; Saha, Anindya; Goldsmith, Paul F; Wang, Jun-Zhi; Zhang, Qizhou; Qin, Sheng-Li; Wang, Ke; Li, Shanghuo; Soam, Archana; Dewangan, Lokesh; Lee, Chang Won; Li, Pak-Shing; Liu, Xun-Chuan; Zhang, Yong; Ren, Zhiyuan; Juvela, Mika; Bronfman, Leonardo; Wu, Yue-Fang; Tatematsu, Ken'ichi; Chen, Xi; Li, Di; Stutz, Amelia; Zhang, Siju; Viktor Toth, L; Luo, Qiu-Yi; Xu, Feng-Wei; Li, Jinzeng; Liu, Rong; Zhou, Jianwen; Zhang, Chao; Tang, Mengyao; Zhang, Chao; Baug, Tapas; Mannfors, E; Chakali, Eswaraiah; Dutta, Somnath;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 510:Issue 4(2022)
• Page Start: 5009
• Page End: 5022
• Publication Date: 2021-11-11
• Subjects: stars: formation -- stars: kinematics and dynamics -- ISM: clouds -- ISM: individual objects: G034.43+00.24; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab2757
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present new 3-mm continuum and molecular lines observations from the ATOMS survey towards the massive protostellar clump, MM1, located in the filamentary infrared dark cloud (IRDC), G034.43+00.24 (G34). The lines observed are the tracers of either dense gas (e.g. HCO + /H 13 CO + J = 1–0) or outflows (e.g. CS J = 2–1). The most complete picture to date of seven cores in MM1 is revealed by dust continuum emission. These cores are found to be gravitationally bound, with virial parameter, α vir < 2. At least four outflows are identified in MM1 with a total outflowing mass of ∼45 M⊙, and a total energy of 1 × 10 47 erg, typical of outflows from a B0-type star. Evidence of hierarchical fragmentation, where turbulence dominates over thermal pressure, is observed at both the cloud and the clump scales. This could be linked to the scale-dependent, dynamical mass inflow/accretion on clump and core scales. We therefore suggest that the G34 cloud could be undergoing a dynamical mass inflow/accretion process linked to the multiscale fragmentation, which leads to the sequential formation of fragments of the initial cloud, clumps, and ultimately dense cores, the sites of star formation.