The Dynamics of Massive Starless Cores with ALMA

Abstract

How do stars that are more massive than the Sun form, and thus how is the stellar initial mass function (IMF) established? Such intermediate- and high-mass stars may be born from relatively massive pre-stellar gas cores, which are more massive than the thermal Jeans mass. The Turbulent Core Accretion model invokes such cores as being in approximate virial equilibrium and in approximate pressure equilibrium with their surrounding clump medium. Their internal pressure is provided by a combination of turbulence and magnetic fields. Alternatively, the Competitive Accretion model requires strongly sub-virial initial conditions that then lead to extensive fragmentation to the thermal Jeans scale, with intermediate- and high-mass stars later forming by competitive Bondi-Hoyle accretion. To test these models, we have identified four prime examples of massive (~100Msun) clumps from mid-infrared extinction mapping of infrared dark clouds (IRDCs). Fontani et al. found high deuteration fractions of N2H+ in these objects, which are consistent with them being starless. Here we present ALMA observations of these four clumps that probe the N2D+(3-2) line at 2.3" resolution. We find six N2D+ cores and determine their dynamical state. Their observed velocity dispersions and sizes are broadly consistent with the predictions of the Turbulent Core model of self-gravitating, magnetized (with Alfven Mach number m_A~1) and virialized cores that are bounded by the high pressures of their surrounding clumps. However, in the most massive cores, with masses up to ~60Msun, our results suggest that moderately enhanced magnetic fields (so that m_A~0.3) may be needed for the structures to be in virial and pressure equilibrium. Magnetically regulated core formation may thus be important in controlling the formation of massive cores, inhibiting their fragmentation, and thus helping to establish the stellar IMF.

Accepted to the Astrophysical Journal, 14 pages

References in corpus (4)

• A Minimum Column Density of 1 g cm^-2 for Massive Star Formation
• Observing the gas temperature drop in the high-density nucleus of L 1544
• Mid-Infrared Extinction Mapping of Infrared Dark Clouds II. The Structure of Massive Starless Cores and Clumps
• The Effect of Magnetic Fields and Ambipolar Diffusion on Core Mass Functions

Cited by in corpus (109)

• Star Clusters Across Cosmic Time
• High-Mass Star and Massive Cluster Formation in the Milky Way
• Low Virial Parameters in Molecular Clouds: Implications for High Mass Star Formation and Magnetic Fields
• Magnetic Fields in High-Mass Infrared Dark Clouds
• The ALMA Survey of 70 $\mu$m dark High-mass clumps in Early Stages (ASHES). I. Pilot Survey: Clump Fragmentation
• Fragmentation of Molecular Clumps and Formation of Protocluster
• A Massive Prestellar Clump Hosting no High-Mass Cores
• Far-Infrared Dust Temperatures and Column Densities of the MALT90 Molecular Clump Sample
• The Hi-GAL compact source catalogue -- II. The 360° catalogue of clump physical properties
• The earliest phases of high-mass star formation, as seen in NGC 6334 by \emph{Herschel}
• ALMA-IMF I -- Investigating the origin of stellar masses: Introduction to the Large Program and first results
• Infall Signatures in a Prestellar Core embedded in the High-Mass 70 $\mu$m Dark IRDC G331.372-00.116
• ALMA survey of massive cluster progenitors from ATLASGAL. Limited fragmentation at the early evolutionary stage of massive clumps
• The Deuterium Fractionation Timescale in Dense Cloud Cores: A Parameter Space Exploration
• A holistic perspective on the dynamics of G035.39-00.33: the interplay between gas and magnetic fields
• An Ordered Bipolar Outflow from a Massive Early-Stage Core
• Evolutionary study of complex organic molecules in high-mass star-forming regions
• ALMA observations of fragmentation, sub-structure, and protostars in high-mass starless clump candidates
• Investigating the structure and fragmentation of a highly filamentary IRDC
• Unveiling the Early-Stage Anatomy of a Protocluster Hub with ALMA
• Massive Outflows Driven by Magnetic Effects in Star Forming Clouds with High Mass Accretion Rates
• Properties of dense cores in clustered massive star-forming regions at high angular resolution
• The Deuterium Fraction in Massive Starless Cores and Dynamical Implications
• ALMA reveals sequential high-mass star formation in the G9.62+0.19 complex
• The Core Mass Function Across Galactic Environments. II. Infrared Dark Cloud Clumps
• Massive 70 micron quiet clumps II: non-thermal motions driven by gravity in massive star formation?
• A Hunt for Massive Starless Cores
• The Core Mass Function in the Massive Protocluster G286.21+0.17 revealed by ALMA
• The ATLASGAL survey: The sample of young massive cluster progenitors
• G11.92-0.61-MM2: A Bonafide Massive Prestellar Core?
• Massive and low-mass protostars in massive "starless" cores
• Widespread Molecular Outflows in the Infrared Dark Cloud G28.37+0.07: Indications of Orthogonal Outflow-Filament Alignment
• Detection of a high-mass prestellar core candidate in W43-MM1
• The Darkest Shadows: Deep Mid-Infrared Extinction Mapping of a Massive Protocluster
• Massive Star Formation via the Collapse of Subvirial and Virialized Turbulent Massive Cores
• Outflow detection in a 70 $\mu$m dark high-mass core
• Surveys of Clumps, Cores, and Condensations in Cygnus X: I. a New Catalog of ~0.1 pc Massive Dense Cores
• High-mass Starless Clumps in the inner Galactic Plane: the Sample and Dust Properties
• Turbulence, Coherence and Collapse: Three Phases for Core Evolution
• Magnetic fields in the early stages of massive star formation as revealed by ALMA
• Magnetically-regulated fragmentation of a massive, dense and turbulent clump
• The core population and kinematics of a massive clump at early stages: an ALMA view
• ALMA-IRDC: Dense gas mass distribution from cloud to core scales
• Temperature structure and kinematics of the IRDC G035.39-00.33
• Magnetic fields at the onset of high-mass star formation
• KFPA Examinations of Young STellar Object Natal Environments (KEYSTONE): Hierarchical Ammonia Structures in Galactic Giant Molecular Clouds
• CN Zeeman and dust polarization in a high-mass cold clump
• Massive Outflows Driven by Magnetic Effects II: Comparison with Observations
• Identification of prestellar cores in high-mass star forming clumps via ${\mathrm{H}}_2{\mathrm{D}}^{+}$ observations with ALMA
• Zooming in to Massive Star Birth
• The fragmentation properties of massive protocluster gas clumps: an ALMA study
• ALMA observations of NGC 6334S. II. Subsonic and Transonic Narrow Filaments in a High-mass Star Formation Cloud
• Kiloparsec-Scale Simulations of Star Formation in Disk Galaxies III. Structure and Dynamics of Filaments and Clumps in Giant Molecular Clouds
• Dynamical cloud formation traced by atomic and molecular gas
• Gravity and rotation drag the magnetic field in high-mass star formation
• Mother of Dragons: A Massive, quiescent core in the dragon cloud (IRDC G028.37+00.07)
• The chemical structure of young high-mass star-forming clumps: (II) parsec-scale CO depletion and deuterium fraction of $\mathrm{HC}{\mathrm{O}}^{+}$
• Failed and delayed protostellar outflows with high mass accretion rates
• Herschel observations of the Galactic HII region RCW 79
• 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
• Lack of high-mass prestellar cores in the starless MDCs of NGC6334
• Surveying the Giant HII Regions of the Milky Way with SOFIA: I. W51A
• Subsonic islands within a high-mass star-forming IRDC
• Are massive dense clumps truly sub-virial? A new analysis using Gould Belt ammonia data
• ALMA-IMF XI: The sample of hot core candidates A rich population of young high-mass proto-stars unveiled by the emission of methyl formate
• ALMA reveals the magnetic field evolution in the high-mass star forming complex G9.62+0.19
• A possible observational bias in the estimation of the virial parameter in virialized clumps
• Rapidly increasing collimation and magnetic field changes of a H2O maser outflow
• Similar complex kinematics within two massive, filamentary infrared dark clouds
• ALMA-IMF. VII. First release of the full spectral line cubes: Core kinematics traced by DCN J=(3-2)
• 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
• Mid-J CO shock tracing observations of infrared dark clouds II Low-J CO constraints on excitation, depletion, and kinematics
• High-Mass Star Formation
• Mid-J CO Shock Tracing Observations of Infrared Dark Clouds III: SLED fitting
• Far-infrared extinction mapping of infrared dark clouds
• Astrochemical modelling of infrared dark clouds
• Star Cluster Formation from Turbulent Clumps. I. The Fast Formation Limit
• Mid-J CO Shock Tracing Observations of Infrared Dark Clouds I
• HII regions and high-mass starless clump candidates I: Catalogs and properties
• Physical Properties of Galactic Planck Cold Cores revealed by the Hi-GAL survey
• Variations of the HCO${}^{+}$, HCN, HNC, N${}_2$H${}^{+}$ and NH${}_3$ deuterium fractionation in high-mass star-forming regions
• Role of environment and gas temperature in the formation of multiple protostellar systems: molecular tracers
• Atacama Large Aperture Submillimeter Telescope (AtLAST) Science: Our Galaxy
• ALMA-IMF XVII -- Census and lifetime of high-mass prestellar cores in 14 massive protoclusters
• Anatomy of the massive star-forming region S106: The OI 63 micron line observed with GREAT/SOFIA as a versatile diagnostic tool for the evolution of massive stars
• Core Emergence in a Massive Infrared Dark Cloud: A Comparison Between Mid-IR Extinction and 1.3 mm Emission
• Gas Kinematics of the Massive Protocluster G286.21+0.17 Revealed by ALMA
• Structure, Dynamics and Deuterium Fractionation of Massive Pre-Stellar Cores
• Deuterium Chemodynamics of Massive Pre-Stellar Cores
• High-Mass Starless Clumps: Dynamical State and Correlation Between Physical Parameters
• Searching for initial stage of massive star formation around the H II region G18.2-0.3
• Highly structured turbulence in high-mass star formation: an evolved infrared dark cloud G35.20-0.74 N
• Deuterium Fractionation across the Infrared Dark Cloud G034.77-00.55 interacting with the Supernova Remnant W44
• Deuteration in infrared dark clouds
• GMC Collisions As Triggers of Star Formation. IV. The Role of Ambipolar Diffusion
• Star Formation in a Strongly Magnetized Cloud
• OH maser toward IRAS 06056+2131: polarization parameters and evolution status
• Sulphur-Bearing and Complex Organic Molecules in an Infrared Cold Core
• Multiwavelength study of the G345.5+1.5 region
• Star formation in IRDC G31.97+0.07
• 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
• ALMAGAL V. Relations between the core populations and the parent clump physical properties
• Binary Formation in a 100 $\mu$m-dark Massive Core
• Comparison of Low-Mass and High-Mass Star Formation
• The Deuteration Clock for Massive Starless Cores
• Fire from Ice - Massive Star Birth from Infrared Dark Clouds
• CHemical Evolution in MassIve star-forming COres (CHEMICO). I. Evolution of the temperature structure
• CO Depletion in Infrared Dark Clouds
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- X. Chemical differentiation among the massive cores in G9.62+0.19