High‐Mass Star Formation. III. The Functional Form of the Submillimeter Clump Mass Function

2006/07/06 by Michael A. Reid, C. D. Wilson, Christine D. Wilson · 4 citations
Chemical Engineering · Mathematics · Physics and Astronomy · #Advanced Combustion Engine Technologies #Astrophysics #Astrophysics and Star Formation Studies #Biology #Exponent #Fragmentation (computing) #Galaxy #Initial mass function #Log-normal distribution #Mass distribution #Mathematics #Physics #Power law #Star formation #Stars #Statistics #Stellar, planetary, and galactic studies #astro-ph

paper · pdf · doi:10.1086/507019

published as Astrophys.J.650:970-984,2006 · 34 pages, 10 figures, accepted for publication in the October 10, 2006 issue of the Astrophysical Journal

arxiv created 2006/07/06 · openalex publication_date 2006/10/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We investigate the mass function of cold, dusty clumps in 11 low- and high-mass star-forming regions. Using a homogeneous fitting technique, we analyze the shape of each region's clump mass function and examine the commonalities among them. We find that the submillimeter continuum clump mass function in low-mass star-forming regions is typically best fitted by a lognormal distribution, while that in high-mass star-forming regions is better fitted by a double power law. A single power-law clump mass distribution is ruled out in all cases. Fitting all of the regions with a double power law, we find that the mean power-law exponent at the high-mass end of each mass function is α high = -2.4 ± 0.1, consistent with the Salpeter result of α = -2.35. We find no region-to-region trend in α high with the mass scale of the clumps in a given region, as characterized by their median mass. Similarly, nonparametric tests show that the shape of the clump mass function does not change much from region to region, despite the obvious changes in the intrinsic mass scale. This result is consistent with the hypothesis that the clump mass distribution is determined by a highly stochastic process, such as turbulent fragmentation. It may also suggest that the data reduction and analysis techniques strongly affect the shape of the derived mass function.

Citations

• The formation of star clusters - I. Three-dimensional simulations of hydrodynamic turbulence
• The Initial Mass Function of Stars: Evidence for Uniformity in Variable Systems
• Massive star formation in 100,000 years from turbulent and pressurized molecular clouds
• Variability in the stellar initial mass function at low and high mass: three-component IMF models
• Accretion and the stellar mass spectrum in small clusters
• The Formation of Massive Stars from Turbulent Cores
• Galactic Stellar and Substellar Initial Mass Function
• The Giant Molecular Cloud associated with RCW 106

Cited by

• Radiation‐Hydrodynamic Simulations of Collapse and Fragmentation in Massive Protostellar Cores
• RADIATION FEEDBACK, FRAGMENTATION, AND THE ENVIRONMENTAL DEPENDENCE OF THE INITIAL MASS FUNCTION
• SIMILARITY BETWEEN THE C18O (J= 1-0) CORE MASS FUNCTION AND THE INITIAL MASS FUNCTION (IMF) IN THE S140 REGION
• The unexpectedly large proportion of high-mass star-forming cores in a Galactic mini-starburst