The role of turbulence in high-mass star formation: Subsonic and transonic turbulence are ubiquitously found at early stages
Journal article, 2024
Context. Traditionally, supersonic turbulence is considered to be one of the most likely mechanisms slowing the gravitational collapse in dense clumps, thereby enabling the formation of massive stars. However, several recent studies have raised differing points of view based on observations carried out with sufficiently high spatial and spectral resolution. These studies call for a re-evaluation of the role turbulence plays in massive star-forming regions. Aims. Our aim is to study the gas properties, especially the turbulence, in a sample of massive star-forming regions with sufficient spatial and spectral resolution, which can both resolve the core fragmentation and the thermal line width. Methods. We observed NH3 metastable lines with the Very Large Array (VLA) to assess the intrinsic turbulence. Results. Analysis of the turbulence distribution histogram for 32 identified NH3 cores reveals the presence of three distinct components. Furthermore, our results suggest that (1) sub-and transonic turbulence is a prevalent (21 of 32) feature of massive star-forming regions and those cold regions are at early evolutionary stage. This investigation indicates that turbulence alone is insufficient to provide the necessary internal pressure required for massive star formation, necessitating further exploration of alternative candidates; and (2) studies of seven multi-core systems indicate that the cores within each system mainly share similar gas properties and masses. However, two of the systems are characterized by the presence of exceptionally cold and dense cores that are situated at the spatial center of each system. Our findings support the hub-filament model as an explanation for this observed distribution.
Radio lines: ISM
Turbulence
ISM: kinematics and dynamics
Submillimeter: ISM
Stars: formation
Author
Chao Wang
Beijing University of Technology
Ke Wang
Beijing University of Technology
Feng Wei Xu
Beijing University of Technology
Patricio Sanhueza
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Hauyu Baobab Liu
National Sun Yat-Sen University
Qizhou Zhang
Harvard-Smithsonian Center for Astrophysics
Xing Lu
Shanghai Astronomical Observatory
Francesco Fontani
Arcetri Astrophysical Observatory
P. Caselli
Max Planck Society
Gemma Busquet
Institute of Space Studies of Catalonia (IEEC)
University of Barcelona
Jonathan Tan
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Di Li
Chinese Academy of Sciences
Zhejiang Lab
J. M. Jackson
Green Bank Observatory
NASA Ames Research Center
University of Virginia
Thushara Pillai
Boston University
Paul T.P. Ho
Academia Sinica
East Asian Observatory
Andrés E. Guzmán
National Astronomical Observatory of Japan
Nannan Yue
Beijing University of Technology
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 681 A51Subject Categories
Astronomy, Astrophysics and Cosmology
Fluid Mechanics and Acoustics
DOI
10.1051/0004-6361/202347024