The ALMA-QUARKS Survey. III. Clump-to-core Fragmentation and Searches for High-mass Starless Cores
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 ( λ obs ) are significantly less than the thermal Jeans length ( λ J ), with the λ obs / λ J 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 λ obs / λ J ≪ 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.
Authors
- Dongting Yang (ORCID: https://orcid.org/0009-0004-6159-5375)
- Xiaofeng Mai (ORCID: https://orcid.org/0000-0001-7573-0145)
- Xindi Tang (ORCID: https://orcid.org/0000-0002-4154-4309)
- Tie Liu (ORCID: https://orcid.org/0000-0002-5286-2564)
- Jihye Hwang (ORCID: https://orcid.org/0000-0001-7866-2686)
- Patricio Sanhueza (ORCID: https://orcid.org/0000-0002-7125-7685)
- Xunchuan Liu (ORCID: https://orcid.org/0000-0001-8315-4248)
- Shanghuo Li (ORCID: https://orcid.org/0000-0003-1275-5251)
- Fengwei Xu (ORCID: https://orcid.org/0000-0001-5950-1932)
- L. K. Dewangan (ORCID: https://orcid.org/0000-0001-6725-0483)
- Prasanta Gorai (ORCID: https://orcid.org/0000-0003-1602-6849)
- Chuanshou Li (ORCID: https://orcid.org/0000-0001-5710-6509)
- Tapas Baug (ORCID: https://orcid.org/0000-0003-0295-6586)
- Xianjin Shen (ORCID: https://orcid.org/0009-0004-3244-3508)
- Anandmayee Tej (ORCID: https://orcid.org/0000-0001-5917-5751)
- Chang Won Lee (ORCID: https://orcid.org/0000-0002-3179-6334)
- Ariful Hoque (ORCID: https://orcid.org/0009-0003-6633-525X)
- Anindya Saha (ORCID: https://orcid.org/0000-0002-9793-3039)
- Wenyu Jiao (ORCID: https://orcid.org/0000-0001-9822-7817)
- Yankun Zhang
- P. F. Goldsmith (ORCID: https://orcid.org/0000-0002-6622-8396)
- Sami Dib (ORCID: https://orcid.org/0000-0002-8697-9808)
- A. Y. Yang (ORCID: https://orcid.org/0000-0003-4546-2623)
- L. Bronfman (ORCID: https://orcid.org/0000-0002-9574-8454)
- A. Zavagno (ORCID: https://orcid.org/0000-0001-9509-7316)
- James O. Chibueze (ORCID: https://orcid.org/0000-0002-9875-7436)
- Ankan Das (ORCID: https://orcid.org/0000-0003-4615-602X)
- Sheng‐Li Qin (ORCID: https://orcid.org/0000-0003-2302-0613)
- Mengyao Tang (ORCID: https://orcid.org/0000-0001-9160-2944)
- Pablo García (ORCID: https://orcid.org/0000-0002-8586-6721)
- Amelia M. Stutz (ORCID: https://orcid.org/0000-0003-2300-8200)
- L. Viktor Tóth (ORCID: https://orcid.org/0000-0002-5310-4212)
- Kotomi Taniguchi (ORCID: https://orcid.org/0000-0003-4402-6475)
- Aina Palau (ORCID: https://orcid.org/0000-0002-9569-9234)
- Jianjun Zhou (ORCID: https://orcid.org/0000-0001-9898-7285)
- Yichen Zhang (ORCID: https://orcid.org/0000-0001-7511-0034)
- Li Chen (ORCID: https://orcid.org/0009-0009-8154-4205)
- Hongli Liu (ORCID: https://orcid.org/0000-0003-3343-9645)
- Tianwei Zhang (ORCID: https://orcid.org/0000-0002-1466-3484)
- Swagat Ranjan Das (ORCID: https://orcid.org/0000-0002-3658-0516)
- J. H. Zou (ORCID: https://orcid.org/0009-0000-9090-9960)
- Guido Garay
- Hafiz Nazeer
- Lei Zhu
- Siju Zhang (ORCID: https://orcid.org/0009-0008-1992-8462)
- Zhiping Kou
Publication Details
- Journal
- The Astrophysical Journal Supplement Series
- Published
- 2025-09-01
- DOI
- https://doi.org/10.3847/1538-4365/adf847
- Citations
- 7
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 8.08