The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). IX. Physical Properties and Spatial Distribution of Cores in IRDCs

Abstract

The initial conditions found in infrared dark clouds (IRDCs) provide insights on how high-mass stars and stellar clusters form. We have conducted high-angular resolution and high-sensitivity observations toward thirty-nine massive IRDC clumps, which have been mosaicked using the 12m and 7m arrays from the Atacama Large Millimeter/submillimeter Array (ALMA). The targets are 70 $\mu$m dark massive (220-4900 $M_{\odot }$), dense ($>$10${}^4$ cm${}^{-3}$), and cold ($\sim$10-20K) clumps located at distances between 2 and 6 kpc. We identify an unprecedented number of 839 cores, with masses between 0.05 and 81 $M_{\odot }$ using 1.3 mm dust continuum emission. About 55% of the cores are low-mass ($<$1 $M_{\odot }$), whereas $\lesssim$1% (7/839) are high-mass ($\gtrsim$27 $M_{\odot }$). We detect no high-mass prestellar cores. The most massive cores (MMC) identified within individual clumps lack sufficient mass to form high-mass stars without additional mass feeding. We find that the mass of the MMCs is correlated with the clump surface density, implying denser clumps produce more massive cores and a larger number of cores. There is no significant mass segregation except for a few tentative detections. In contrast, most clumps show segregation once the clump density is considered instead of mass. Although the dust continuum emission resolves clumps in a network of filaments, some of which consist of hub-filament systems, the majority of the MMCs are not found in the hubs. Our analysis shows that high-mass cores and MMCs have no preferred location with respect to low-mass cores at the earliest stages of high-mass star formation.

Accepted for Publication in ApJ. 54 pages, 40 figures, 5 tables

References in corpus (41)

• The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Structural Analysis of Molecular Clouds: Dendrograms
• Filamentary structure of star-forming complexes
• ATLASGAL --- properties of a complete sample of Galactic clumps
• A Minimum Column Density of 1 g cm^-2 for Massive Star Formation
• ATLASGAL --- towards a complete sample of massive star forming clumps
• Using the minimum spanning tree to trace mass segregation
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• Magnetic Fields and Massive Star Formation
• Fragmentation of Molecular Clumps and Formation of Protocluster
• The dynamical properties of dense filaments in the infrared dark cloud G035.39-00.33
• Properties of the dense core population in Orion B as seen by the Herschel Gould Belt survey
• Filamentary Accretion Flows in the Infrared Dark Cloud G14.225-0.506 Revealed by ALMA
• Gravity Driven Magnetic Field at ~1000 au Scales in High-mass Star Formation
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- XI. From inflow to infall in hub-filament systems
• Dense core properties in the Infrared Dark cloud G14.225-0.506 revealed by ALMA
• The W43-MM1 mini-starburst ridge, a test for star formation efficiency models
• Infall Motions in Massive Star-Forming Regions: Results from Years 1 & 2 of the MALT90 Survey
• The ALMA Survey of 70 $\mu \mathrm{m}$ Dark High-mass Clumps in Early Stages (ASHES). II: Molecular Outflows in the Extreme Early Stages of Protocluster Formation
• Comparisons between different techniques for measuring mass segregation
• Evidence of high-mass star formation through multi-scale mass accretion in hub-filament-system clouds
• Massive and low-mass protostars in massive "starless" cores
• Characterizing the properties of cluster precursors in the MALT90 survey
• The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII. Dynamics of Embedded Dense Cores
• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). IV. Star formation signatures in G023.477
• Physical Properties of the star-forming clusters in NGC 6334
• 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
• Establishing the evolutionary timescales of the massive star formation process through chemistry
• ALMA-IRDC: Dense gas mass distribution from cloud to core scales
• The core population and kinematics of a massive clump at early stages: an ALMA view
• HII regions and high-mass starless clump candidates II. Fragmentation and induced star formation at ~0.025 pc scale: An ALMA continuum study
• Initial Fragmentation in the Infrared Dark Cloud G28.53-0.25
• The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VI. The core-scale CO-depletion
• The chemical structure of young high-mass star-forming clumps: (II) parsec-scale CO depletion and deuterium fraction of $\mathrm{HC}{\mathrm{O}}^{+}$
• The ALMA Survey of 70 $\mu \mathrm{m}$ Dark High-mass Clumps in Early Stages (ASHES). VII: Chemistry of Embedded Dense Cores
• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). V. Deuterated Molecules in the 70 $\mu$m dark IRDC G14.492-00.139
• The ALMA Survey of 70$\mu$m Dark High-mass Clumps in Early Stages (ASHES) III. A Young Molecular Outflow Driven by a Decelerating Jet
• A Low-mass Cold and Quiescent Core Population in a Massive Star Protocluster
• ALMA Observations of the IRDC Clump G34.43+00.24 MM3: DNC/HNC Ratio

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• Direct observational evidence of the multi-scale, dynamical mass accretion toward a high-mass star forming hub-filament system
• The dynamic centres of infrared-dark clouds and the formation of cores
• Constraints on the (re-)orientation of star-disk systems through infall
• ALMA-IMF X -- The core population in the evolved W33-Main (G012.80) protocluster
• ALMA-IMF XVII -- Census and lifetime of high-mass prestellar cores in 14 massive protoclusters
• Benchmarking the IRDC G351.77-0.53: Gaia DR3 distance, mass distribution, and star formation content
• On the origin of planetary-mass objects in NGC1333
• Emergence of high-mass stars in complex fiber networks (EMERGE) V. From filaments to spheroids: the origin of the hub-filament systems
• Digging into the Interior of Hot Cores with ALMA (DIHCA). V. Deuterium Fractionation of Methanol
• ALMAGAL VI. The spatial distribution of dense cores during the evolution of cluster-forming massive clump
• ALMAGAL V. Relations between the core populations and the parent clump physical properties
• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). XII. Unanchored Forked Stream in the Propagating Path of a Protostellar Outflow
• Molecular deuterations in massive Starless Clump Candidates
• Prestellar Cores in Turbulent Clouds: Properties of Critical Cores
• Dense Molecular Ring-like structure in gaseous CO depletion region G34.74-0.12
• Evolution of compressed clouds formed by filament coalescence. I. Oblique collisions
• Mass Segregation in the CMZoom Survey
• ALMA-IMF VIII -- Combination of Interferometric Continuum Images with Single-Dish Surveys and Structural Analysis of Six Protoclusters
• Formation of massive multiple-star systems: early migration and mergers