The Astrophysical Journal Letters (Jan 2025)
Subclustering and Star Formation Efficiency in Three Protoclusters in the Central Molecular Zone
- Suinan Zhang,
- Xing Lu,
- Adam Ginsburg,
- Nazar Budaiev,
- Yu Cheng,
- Hauyu Baobab Liu,
- Tie Liu,
- Qizhou Zhang,
- Keping Qiu,
- Siyi Feng,
- Thushara Pillai,
- Xindi Tang,
- Elisabeth A. C. Mills,
- Qiuyi Luo,
- Shanghuo Li,
- Namitha Issac,
- Xunchuan Liu,
- Fengwei Xu,
- Jennifer Wallace,
- Xiaofeng Mai,
- Yan-Kun Zhang,
- Cara Battersby,
- Steven N. Longmore,
- Zhiqiang Shen
Affiliations
- Suinan Zhang
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Xing Lu
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Adam Ginsburg
- ORCiD
- Department of Astronomy, University of Florida , P.O. Box 112055, Gainesville, FL 32611, USA
- Nazar Budaiev
- ORCiD
- Department of Astronomy, University of Florida , P.O. Box 112055, Gainesville, FL 32611, USA
- Yu Cheng
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Hauyu Baobab Liu
- ORCiD
- Department of Physics, National Sun Yat-Sen University , No. 70, Lien-Hai Road, Kaohsiung City 80424, Taiwan, ROC; Center of Astronomy and Gravitation, National Taiwan Normal University , Taipei 116, Taiwan
- Tie Liu
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Qizhou Zhang
- ORCiD
- Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
- Keping Qiu
- ORCiD
- School of Astronomy and Space Science, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, People’s Republic of China; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) , Ministry of Education, Nanjing 210023, People’s Republic of China
- Siyi Feng
- ORCiD
- Department of Astronomy, Xiamen University , Zengcuo’an West Road, Xiamen, 361005, People’s Republic of China
- Thushara Pillai
- ORCiD
- Haystack Observatory, Massachusetts Institute of Technology , 99 Millstone Road, Westford, MA 01886, USA
- Xindi Tang
- ORCiD
- Xinjiang Astronomical Observatory , 150 Science 1-Street, Urumqi, Xinjiang 830011, People’s Republic of China; University of Chinese Academy of Sciences , Beijing 100080, People’s Republic of China; Key Laboratory of Radio Astronomy, Chinese Academy of Sciences , Urumqi 830011, People’s Republic of China; Xinjiang Key Laboratory of Radio Astrophysics , Urumqi 830011, People’s Republic of China
- Elisabeth A. C. Mills
- ORCiD
- Department of Physics and Astronomy, University of Kansas , 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA
- Qiuyi Luo
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Shanghuo Li
- ORCiD
- School of Astronomy and Space Science, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, People’s Republic of China
- Namitha Issac
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Xunchuan Liu
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Fengwei Xu
- ORCiD
- I. Physikalisches Institut, Universität zu Köln , Zülpicher Str. 77, D-50937 Köln, Germany; Kavli Institute for Astronomy and Astrophysics, Peking University , Beijing 100871, People’s Republic of China; Department of Astronomy, School of Physics, Peking University , Beijing 100871, People’s Republic of China
- Jennifer Wallace
- ORCiD
- Department of Physics, University of Connecticut , 196A Auditorium Road, Storrs, CT 06269, USA
- Xiaofeng Mai
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Yan-Kun Zhang
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- Cara Battersby
- ORCiD
- Department of Physics, University of Connecticut , 196A Auditorium Road, Storrs, CT 06269, USA
- Steven N. Longmore
- ORCiD
- Astrophysics Research Institute, Liverpool John Moores University , IC 2, Liverpool Science Park, 146 Brownlow Hill, Liverpool, L3 5RF, UK; Cosmic Origins Of Life (COOL) Research DAO, Munich, Germany 22
- Zhiqiang Shen
- ORCiD
- Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People’s Republic of China ; [email protected]
- DOI
- https://doi.org/10.3847/2041-8213/adb30b
- Journal volume & issue
-
Vol. 982,
no. 1
p. L10
Abstract
We present the highest-resolution (∼0 $\mathop{.}\limits^{^{\prime\prime} }$ 04) Atacama Large Millimeter/submillimeter Array 1.3 mm continuum observations so far of three massive star-forming clumps in the Central Molecular Zone (CMZ), namely 20 km s ^−1 C1, 20 km s ^−1 C4, and Sgr C C4, which reveal prevalent compact millimeter emission. We extract the compact emission with astrodendro and identify a total of 199 fragments with a typical size of ∼370 au, which represent the first sample of candidates of protostellar envelopes and disks and kernels of prestellar cores in these clumps that are likely forming star clusters. Compared with the protoclusters in the Galactic disk, the three protoclusters display a higher level of hierarchical clustering, likely a result of the stronger turbulence in the CMZ clumps. Compared with the mini-starbursts in the CMZ, Sgr B2 M and N, the three protoclusters also show stronger subclustering in conjunction with a lack of massive fragments. The efficiency of high-mass star formation of the three protoclusters is on average 1 order of magnitude lower than that of Sgr B2 M and N, despite a similar overall efficiency of converting gas into stars. The lower efficiency of high-mass star formation in the three protoclusters is likely attributed to hierarchical cluster formation.
Keywords
