The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). XIII. Core Mass Function, Lifetime, and Growth of Prestellar Cores
Journal article, 2026
The core mass function (CMF) of prestellar cores is essential for understanding the initial conditions of star and cluster formation. However, the universality of the CMF and its relationship to the initial mass function (IMF) remain unclear. We study the CMF in the earliest stage of high-mass star formation using 461 prestellar core candidates and 254 protostellar cores as a part of the ALMA Survey of 70 mu m Dark High-mass Clumps in Early Stages (ASHES). We find that prestellar core candidates tend to have lower masses than protostellar cores. We also find that the lifetime of prestellar cores is several times longer than the freefall time, although it approaches the freefall time as the core mass increases. The CMF, including both protostellar and prestellar cores, has a power-law slope of -2.05 +/- 0.04, shallower than Salpeter's IMF slope of -2.35. Conversely, the CMF of gravitationally bound, prestellar cores has a steeper slope (-2.32 +/- 0.30), indistinguishable from Salpeter's slope. This finding is consistent with observations in both low-mass star-forming regions and high-mass protoclusters, implying a universal core formation mechanism. The protostellar CMF with a larger maximum core mass can be reproduced by the prestellar CMF when an external gas infall is considered. The inferred mass infall rate is higher than the Bondi-Hoyle-Lyttleton accretion rate and follows a shallower mass dependence (smaller power-law index), more consistent with the tidal-lobe accretion. This may contribute to the evolution of CMFs seen in later stages.
Author
Kaho Morii
National Institutes of Natural Sciences
Harvard-Smithsonian Center for Astrophysics
University of Tokyo
Patricio Sanhueza
University of Tokyo
Q. Zhang
Harvard-Smithsonian Center for Astrophysics
Giovanni Sabatini
Istituto nazionale di astrofisica (INAF)
Shanghuo Li
Nanjing University
Fabien Louvet
Grenoble Alpes University
Henrik Beuther
Max Planck Society
Fernando A. Olguin
Kyoto University
National Institutes of Natural Sciences
Shuting Lin
Xiamen University
Daniel Tafoya
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Takeshi Sakai
University of Electro-Communications
Xing Lu
Chinese Academy of Sciences
Fumitaka Nakamura
University of Tokyo
National Institutes of Natural Sciences
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 997 2 155Subject Categories (SSIF 2025)
Multidisciplinary Geosciences
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/1538-4357/ae25f6