2025-09-10 中国科学院（CAS）
Detection of molecular lines inside the massive prestellar core. (Image by LIU Tie)
＜関連情報＞
- https://english.cas.cn/newsroom/research_news/phys/202509/t20250911_1054384.shtml
- https://iopscience.iop.org/article/10.3847/1538-4365/adf847
ALMA-QUARKSサーベイ。III. 塊から中心部への分断と高質量星のない中心部の探索 The ALMA-QUARKS Survey. III. Clump-to-core Fragmentation and Searches for High-mass Starless Cores
Dongting Yang, Hong-Li Liu, Tie Liu, Xunchuan Liu, Fengwei Xu, Sheng-Li Qin, Anandmayee Tej, Guido Garay, Lei Zhu, Xiaofeng Mai,…
The Astrophysical Journal Supplement Series Published: 2025 September 3
DOI:10.3847/1538-4365/adf847
Abstract
The Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures (QUARKS) survey observed 139 infrared-bright (IR-bright) massive protoclusters at 1.3 mm wavelength with the Atacama Large Millimeter/submillimeter Array (ALMA). This study investigates clump-to-core fragmentation and searches for candidate high-mass starless cores within IR-bright clumps using combined ALMA 12 m (C-2) and Atacama Compact Array 7 m data, providing ∼1″ (∼0.02 pc at 3.7 kpc) resolution and ∼0.6 mJy beam−1 continuum sensitivity (∼0.3 M⊙ at 30 K). We identified 1562 compact cores from 1.3 mm continuum emission using getsf. Observed linear core separations (λobs) are significantly less than the thermal Jeans length (λJ), with the λobs/λJ ratios peaking at ∼0.2. This indicates that thermal Jeans fragmentation has taken place within the IR-bright protocluster clumps studied here. The observed low ratio of λobs/λJ ≪ 1 could be the result of evolving core separation or hierarchical fragmentation. Based on associated signatures of star formation (e.g., outflows and ionized gas), we classified cores into three categories: 127 starless, 971 warm, and 464 evolved cores. Two starless cores have masses exceeding 16 M⊙, and represent high-mass candidates. The scarcity of such candidates suggests that competitive accretion-type models could be more applicable than turbulent core accretion-type models in high-mass star formation within these IR-bright protocluster clumps.
