ALMA-IMF VI -- Investigating the origin of stellar masses: Core mass function evolution in the W43-MM2&MM3 mini-starburst

Abstract

Among the most central open questions regarding the initial mass function (IMF) of stars is the impact of environment on the shape of the core mass function (CMF) and thus potentially on the IMF. The ALMA-IMF Large Program aims to investigate the variations in the core distributions with cloud characteristics, as diagnostic observables of the formation process and evolution of clouds. The present study focuses on the W43-MM2&MM3 mini-starburst, whose CMF has recently been found to be top-heavy with respect to the Salpeter slope. W43-MM2&MM3 harbors a rich cluster that contains a statistically significant number of cores, which was previously characterized in Paper III. We applied a multi-scale decomposition technique to the ALMA 1.3 mm and 3 mm continuum images to define six subregions. For each subregion we characterized the high column density probability distribution function, n-PDF, and the shape of the cloud gas using the 1.3 mm image. Using the core catalog, we investigate correlations between the CMF and cloud and core properties. We classify the subregions into different stages of evolution, from quiescent to burst to post-burst, based on the surface number density of cores, number of outflows, and UCHii presence. The high-mass end of the subregion CMFs varies from being close to the Salpeter slope (quiescent) to top-heavy (burst and post-burst). Moreover, the second tail of the n-PDF varies from steep, to flat like observed for the high mass star-forming clouds. We found that subregions with flat second n-PDF tails display top-heavy CMFs. The CMF may evolve from Salpeter to top-heavy throughout the star formation process from the quiescent to the burst phase. This scenario raises the question of if the CMF might revert again to Salpeter as the cloud approaches the end of its star formation stage, a hypothesis that remains to be tested.

Accepted for publication in A&A (december, 5th 2022) after language editing; 25 pages, 14 figures

References in corpus (40)

• Power-law distributions in empirical data
• Theory of Star Formation
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• What determines the density structure of molecular clouds ? A case study of Orion B with Herschel
• Dynamical mass segregation on a very short timescale
• An excess of massive stars in the local 30 Doradus starburst
• Evolution of column density distributions within Orion~A
• Properties of the dense core population in Orion B as seen by the Herschel Gould Belt survey
• Class 0 Protostars in the Perseus Molecular Cloud: A Correlation Between the Youngest Protostars and the Dense Gas Distribution
• The Arches Cluster Mass Function
• Variations in the initial mass function in early-type galaxies: A critical comparison between dynamical and spectroscopic results
• Gravity Driven Magnetic Field at ~1000 au Scales in High-mass Star Formation
• ALMA-IMF I -- Investigating the origin of stellar masses: Introduction to the Large Program and first results
• Structure and mass segregation in Galactic stellar clusters
• The shapes of column density PDFs - The importance of the last closed contour
• From diffuse gas to dense molecular cloud cores
• The formation of the W43 complex: constraining its atomic-to-molecular transition and searching for colliding clouds
• The W43-MM1 mini-starburst ridge, a test for star formation efficiency models
• Comparisons between different techniques for measuring mass segregation
• Bondi-Hoyle-Littleton accretion and the upper mass stellar IMF
• Tracing extended low-velocity shocks through SiO emission - Case study of the W43-MM1 ridge
• Cloud Structure of Galactic OB Cluster Forming Regions from Combining Ground and Space Based Bolometric Observations
• Understanding star formation in molecular clouds IV. Column density PDFs from quiescent to massive molecular clouds
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
• ALMA-IMF. V. Prestellar and protostellar core populations in the W43 cloud complex
• Mass segregation and sequential star formation in NGC 2264 revealed by Herschel
• Digging into the Interior of Hot Cores with ALMA (DIHCA). I. Dissecting the High-mass Star-Forming Core G335.579-0.292 MM1
• The JCMT Gould Belt Survey: Dense Core Clusters in Orion A
• ALMA-IMF II -- investigating the origin of stellar masses: Continuum Images and Data Processing
• The Formation of Very Massive Stars
• Evolution of the density PDF in star forming clouds: the role of gravity
• The density structure of supersonic self-gravitating turbulence
• Star-forming filament models
• How magnetic field and stellar radiative feedback influences the collapse and the stellar mass spectrum of a massive star forming clump
• Unveiling a cluster of protostellar disks around the massive protostar GGD27 MM1
• The Core Mass Function in the Orion Nebula Cluster Region: What Determines the Final Stellar Masses?
• Large-scale Map of Millimeter-wavelength Hydrogen Radio Recombination Lines around a Young Massive Star Cluster
• Recombination Lines and Molecular Gas from Hypercompact HII regions in W51 A
• Shell instability of a collapsing dense core

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• The dynamic centres of infrared-dark clouds and the formation of cores
• ALMA-IMF X -- The core population in the evolved W33-Main (G012.80) protocluster
• ALMA-IMF XIII: N${}_2$H${}^{+}$ kinematic analysis on the intermediate protocluster G353.41
• ALMA-IMF XVI: Mass-averaged temperature of cores and protostellar luminosities in the ALMA-IMF protoclusters
• ALMA-IMF XVII -- Census and lifetime of high-mass prestellar cores in 14 massive protoclusters
• ALMA-IMF XVIII: The assembly of a star cluster: Dense N${}_2$H${}^{+}$ (1-0) kinematics in the massive G351.77 protocluster
• Emergence of high-mass stars in complex fiber networks (EMERGE) II. The need for data combination in ALMA observations
• ALMAGAL VI. The spatial distribution of dense cores during the evolution of cluster-forming massive clump
• The JCMT Gould Belt Survey Complete Core Catalogue: Core mass function variations between nearby molecular clouds
• Comparing the morphology of molecular clouds without supervision
• Linear filament and nested cluster evolution tomography (LANCET) I. Capture the evolution of dense gas in 14-parsec filament G316.8
• Sub-kpc scale gas density histogram of the Galactic molecular gas: a new statistical method to characterise galactic-scale gas structures
• ALMA-IMF VIII -- Combination of Interferometric Continuum Images with Single-Dish Surveys and Structural Analysis of Six Protoclusters
• Mass Segregation in the CMZoom Survey
• The fragmentation properties of massive star-forming regions in 30Dor-10 at 2000 au resolution
• Cavendish experiment with fast radio bursts on cosmological scales