ALMA-IMF I -- Investigating the origin of stellar masses: Introduction to the Large Program and first results

Abstract

The ALMA-IMF Large Program imaged a total noncontiguous area of 53pc2, covering 15 extreme, nearby protoclusters of the Milky Way. They were selected to span relevant early protocluster evolutionary stages. Our 1.3mm and 3mm observations provide continuum images that are homogeneously sensitive to point-like cores with masses of 0.2 and 0.6Msun, respectively, with a matched spatial resolution of 2000au. We also detect lines that probe the protocluster structure, kinematics, chemistry, and feedback over scales from clouds to filaments to cores. We classify ALMA-IMF protoclusters as Young, Intermediate, or Evolved based on the amount of dense gas in the cloud that has potentially been impacted by HII regions. The ALMA-IMF catalog contains 700 cores that span a mass range of 0.15-250Msun at a typical size of 2100au. We show that this core sample has no significant distance bias and can be used to build core mass functions at similar physical scales. Significant gas motions, which we highlight here in the G353.41 region, are traced down to core scales and can be used to look for inflowing gas streamers and to quantify the impact of the possible associated core mass growth on the shape of the CMF with time. Our first analysis does not reveal any significant evolution of the matter concentration from clouds to cores or from the youngest to more evolved protoclusters, indicating that cloud dynamical evolution and stellar feedback have for the moment only had a slight effect on the structure of high-density gas in our sample. Furthermore, the first-look analysis of the line richness toward bright cores indicates that the survey encompasses several tens of hot cores, of which we highlight the most massive in the G351.77 cloud. Their homogeneous characterization can be used to constrain the emerging molecular complexity in protostars of high to intermediate masses.

arXiv comment27 pages, 9 figures, accepted for publication by A&A

References in corpus (149)

• Galactic Stellar and Substellar Initial Mass Function
• On the variation of the Initial Mass Function
• Cosmic Star Formation History
• Theory of Star Formation
• Trigonometric Parallaxes of High Mass Star Forming Regions: the Structure and Kinematics of the Milky Way
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• A Universal Stellar Initial Mass Function? A Critical Look at Variations
• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• ATLASGAL - The APEX Telescope Large Area Survey of the Galaxy at 870 microns
• High-Mass Proto-Stellar Candidates - II : Density structure from dust continuum and CS emission
• High-Mass Star and Massive Cluster Formation in the Milky Way
• The mass function of dense molecular cores and the origin of the IMF
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• Global collapse of molecular clouds as a formation mechanism for the most massive stars
• Global Hierarchical Collapse In Molecular Clouds. Towards a Comprehensive Scenario
• Dynamic star formation in the massive DR21 filament
• Turbulent molecular clouds
• Star formation in clusters: a survey of compact mm-wave sources in the Serpens core
• Gas and grain chemical composition in cold cores as predicted by the Nautilus 3-phase model
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X
• Stellar Populations in the Central 0.5 pc of the Galaxy II: The Initial Mass Function
• What controls star formation in the central 500 pc of the Galaxy?
• The Red MSX Source Survey: the Massive Young Stellar Population of our Galaxy
• Evidence for top-heavy stellar initial mass functions with increasing density and decreasing metallicity
• An excess of massive stars in the local 30 Doradus starburst
• The stellar and sub-stellar IMF of simple and composite populations
• Stellar populations dominated by massive stars in dusty starburst galaxies across cosmic time
• An ALMA study of the Orion Integral Filament: I. Evidence for narrow fibers in a massive cloud
• The ATLASGAL survey: a catalog of dust condensations in the Galactic plane
• Ammonia from cold high-mass clumps discovered in the inner Galactic disk by the ATLASGAL survey
• The spine of the swan: A Herschel study of the DR21 ridge and filaments in Cygnus X
• Planck Early Results XXIV: Dust in the diffuse interstellar medium and the Galactic halo
• Fragmentation at the Earliest Phase of Massive Star Formation
• Magnetic Fields and Massive Star Formation
• The ALMA Survey of 70 $\mu$m dark High-mass clumps in Early Stages (ASHES). I. Pilot Survey: Clump Fragmentation
• From Massive Protostars to a Giant HII Region: Submillimeter Imaging of the Galactic Mini-starburst W43
• Fragmentation and mass segregation in the massive dense cores of Cygnus X
• The Simultaneous Formation of Massive Stars and Stellar Clusters
• Fragmentation of Molecular Clumps and Formation of Protocluster
• Trigonometric Parallax of W51 Main/South
• A SCUBA survey of the NGC 2068/2071 protoclusters
• The Origin of Massive Stars: The Inertial-Inflow Model
• The Dynamics of Massive Starless Cores with ALMA
• The dynamical properties of dense filaments in the infrared dark cloud G035.39-00.33
• Parsec-scale SiO Emission in an Infrared Dark Cloud
• UCLCHEM: A Gas-Grain Chemical Code
• The unexpectedly large proportion of high-mass star-forming cores in a Galactic mini-starburst
• Questioning the spatial origin of complex organic molecules in young protostars with the CALYPSO survey
• CO outflows from high-mass Class 0 protostars in Cygnus-X
• The Dawes Review 8: Measuring the Stellar Initial Mass Function
• L1157-B1, a factory of complex organic molecules in a Solar-type star forming region
• Evolution of column density distributions within Orion~A
• Slingshot Mechanism in Orion: Kinematic Evidence For Ejection of Protostars by Filaments
• CARMA observations of protostellar outflows in NGC 1333
• Dynamics of cluster-forming hub-filament systems: The case of the high-mass star-forming complex Monoceros R2
• Gas dynamics in Massive Dense Cores in Cygnus-X
• Low-velocity shocks traced by extended SiO emission along the W43 ridges: witnessing the formation of young massive clusters
• Filamentary Fragmentation and Accretion in High-Mass Star-Forming Molecular Clouds
• The Herschel view of massive star formation in G035.39--00.33: Dense and cold filament of W48 undergoing a mini-starburst
• CARMA Large Area Star Formation Survey: Observational Analysis of Filaments in the Serpens South Molecular Cloud
• From the Convergence of Filaments to Disk-Outflow Accretion: Massive-Star Formation in W33A
• Warm SiO gas in molecular bullets associated with protostellar outflows
• The Early Evolution of Massive Stars: Radio Recombination Line Spectra
• The Hi-GAL compact source catalogue -- II. The 360° catalogue of clump physical properties
• ATLASGAL - Kinematic distances and the dense gas mass distribution of the inner Galaxy
• Variations in the initial mass function in early-type galaxies: A critical comparison between dynamical and spectroscopic results
• ATLASGAL-selected massive clumps in the inner Galaxy III. Dust Continuum Characterization of an Evolutionary Sample
• The complex chemistry of hot cores in Sagittarius B2(N): Influence of cosmic-ray ionization and thermal history
• Early stages of cluster formation: fragmentation of massive dense cores down to ~1000 AU
• The Unusual Initial Mass Function of the Arches Cluster
• 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
• Exploring molecular complexity with ALMA (EMoCA): Detection of three new hot cores in Sagittarius B2(N)
• Trigonometric parallaxes to star-forming regions within 4 kpc of the galactic center
• Detection of two power-law tails in the probability distribution functions of massive GMCs
• Distinct Chemical Regions in the "Prestellar" Infrared Dark Cloud (IRDC) G028.23-00.19
• The physical and chemical structure of Sagittarius B2. II. Continuum millimeter emission of SgrB2(M) and SgrB2(N) with ALMA
• ATLASGAL-selected massive clumps in the inner Galaxy: V. Temperature structure and evolution
• There are no starless massive proto-clusters in the first quadrant of the Galaxy
• Spectrophotometric Distances to Galactic H\,{\sc{ii}} Regions
• SMA millimeter observations of Hot Molecular Cores
• Cluster Formation Triggered by Filament Collisions in Serpens South
• Galactic cold cores VI. Dust opacity spectral index
• Probing the formation of intermediate- to high-mass stars in protoclusters II. Comparison between millimeter interferometric observations of NGC 2264-C and SPH simulations of a collapsing clump
• Formation of an O-Star Cluster by Hierarchical Accretion in G20.08-0.14 N
• Multiscale, multiwavelength extraction of sources and filaments using separation of the structural components: getsf
• Trigonometric Parallaxes of Massive Star Forming Regions: G012.88+0.48 and W33
• From diffuse gas to dense molecular cloud cores
• Dense core properties in the Infrared Dark cloud G14.225-0.506 revealed by ALMA
• MUSCLE W49 : A Multi-Scale Continuum and Line Exploration of the Most Luminous Star Formation Region in the Milky Way. I. Data and The Mass Structure of the Giant Molecular Cloud
• The W43-MM1 mini-starburst ridge, a test for star formation efficiency models
• Convergent flows and low-velocity shocks in DR21(OH)
• Thermal Feedback in the high-mass star and cluster forming region W51
• Connection between dense gas mass fraction, turbulence driving, and star formation efficiency of molecular clouds
• SiO emission from low- and high-velocity shocks in Cygnus-X massive dense clumps
• Antifreeze in the hot core of Orion - First detection of ethylene glycol in Orion-KL
• 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
• The RWST, a comprehensive statistical description of the non-Gaussian structures in the ISM
• The Core Mass Function Across Galactic Environments. II. Infrared Dark Cloud Clumps
• ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact
• Tracing extended low-velocity shocks through SiO emission - Case study of the W43-MM1 ridge
• The Onset of Massive Star Formation: The Evolution of Temperature and Density Structure in an Infrared Dark Cloud
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
• The ATLASGAL survey: The sample of young massive cluster progenitors
• The search for high-mass protostars with ALMA revealed up to kilo-parsec scales (SPARKS): I. Indication for a centrifugal barrier in the environment of a single high-mass envelope
• Episodic accretion constrained by a rich cluster of outflows
• Formation of the Musca filament: Evidence for asymmetries in the accretion flow due to a cloud-cloud collision
• The dense gas mass fraction in the W51 cloud and its protoclusters
• The Origin of the Stellar Mass Distribution and Multiplicity
• Detection of a high-mass prestellar core candidate in W43-MM1
• Diversity of chemistry and excitation conditions in the high-mass star forming complex W33
• A measurement of the turbulence-driven density distribution in a non-star-forming molecular cloud
• Slingshot Mechanism for Clusters: Gas Density Regulates Star Density in the Orion Nebula Cluster (M42)
• Seeds of Life in Space (SOLIS). X. Interstellar Complex Organic Molecules in the NGC 1333 IRAS 4A outflows
• An analysis of star formation with Herschel in the Hi-GAL Survey. I. The Science Demonstration Phase Fields
• Gas flows around 2 young stellar clusters in NGC2264
• Physical Properties of the star-forming clusters in NGC 6334
• Mass segregation and sequential star formation in NGC 2264 revealed by Herschel
• ALMA-IMF II -- investigating the origin of stellar masses: Continuum Images and Data Processing
• Digging into the Interior of Hot Cores with ALMA (DIHCA). I. Dissecting the High-mass Star-Forming Core G335.579-0.292 MM1
• The Formation of Very Massive Stars
• On the chemical ladder of esters. Detection and formation of ethyl formate in the W51 e2 hot molecular core
• The Decrease of Specific Angular Momentum and the Hot Toroid Formation: The Massive Clump G10.6-0.4
• Asymmetric Line Profiles in Dense Molecular Clumps Observed in MALT90: Evidence for Global Collapse
• Submillimeter spectroscopy of southern hot cores: NGC6334(I) and G327.3-0.6
• Investigating fragmentation of gas structures in OB cluster-forming molecular clump G33.92+0.11 with 1000 AU resolution observations of ALMA
• Herschel Gould Belt Survey Observations of Dense Cores in the Cepheus Flare Clouds
• Molecular analysis of a high-mass prestellar core candidate in W43-MM1
• A new study of the chemical structure of the Horsehead nebula: the influence of grain-surface chemistry
• ATLASGAL - Ammonia observations towards the southern Galactic Plane
• Rotation of molecular clouds in M~51
• Gas velocity structure of the Orion A Integral Shaped Filament
• Misaligned Twin Molecular Outflows From Class-0 Proto-stellar Binary System VLA 1623A Unveiled by ALMA
• Strong dependence of the physical properties of cores on spatial resolution in observations and simulations
• Young and embedded clusters in Cygnus-X: evidence for building up the IMF?
• From forced collapse to H ii region expansion in Mon R2: Envelope density structure and age determination with Herschel
• Fragmentation and filaments at the onset of star and cluster formation: SABOCA 350 $\mu$m view of ATLASGAL selected massive clumps
• Lack of high-mass prestellar cores in the starless MDCs of NGC6334
• Dimethyl ether in its ground state, v=0, and lowest two torsionally excited states, v11=1 and v15=1, in the high-mass star-forming region G327.3-0.6
• Filament rotation in the California L1482 cloud
• The MUSTANG-2 Galactic Plane Survey (MGPS90) pilot
• Ammonia in the hot core W51-IRS2: 12 new maser lines and a maser component with a velocity drift
• High mass star formation in the IRAS 17233-3606 region: a new nearby and bright hot core in the southern sky
• 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
• The complexity of Orion: an ALMA view III. The explosion impact
• The Core Mass Function Across Galactic Environments. III. Massive Protoclusters
• The Herschel Orion Protostar Survey: Far-Infrared Photometry and Colors of Protostars and Their Variations across Orion A and B
• Infall, outflow, and turbulence in massive star-forming cores in the G333 giant molecular cloud

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• Evidence of high-mass star formation through multi-scale mass accretion in hub-filament-system clouds
• ALMA-IMF. V. Prestellar and protostellar core populations in the W43 cloud complex
• ALMA-IMF VI -- Investigating the origin of stellar masses: Core mass function evolution in the W43-MM2&MM3 mini-starburst
• ALMA-IMF II -- investigating the origin of stellar masses: Continuum Images and Data Processing
• The SQUALO project (Star formation in QUiescent And Luminous Objects) I: clump-fed accretion mechanism in high-mass star-forming objects
• ALMA-IMF XV: The core mass function in the high-mass star-formation regime
• The Evolution of Protostellar Outflow Cavities, Kinematics, and Angular Distribution of Momentum and Energy in Orion A: Evidence for Dynamical Cores
• 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-IMF. VII. First release of the full spectral line cubes: Core kinematics traced by DCN J=(3-2)
• The dynamic centres of infrared-dark clouds and the formation of cores
• Unveiling the formation of the massive DR21 ridge
• ALMA-IMF IV -- A comparative study of the main hot cores in W43-MM1: detection, temperature and molecular composition
• ALMA-IMF X -- The core population in the evolved W33-Main (G012.80) protocluster
• An updated modular set of synthetic spectral energy distributions for young stellar objects
• ALMA-IMF XIII: N${}_2$H${}^{+}$ kinematic analysis on the intermediate protocluster G353.41
• Emergence of high-mass stars in complex fiber networks (EMERGE). I. Early ALMA Survey: observations and massive data reduction
• Complex organic molecules uncover deeply embedded precursors of hot cores
• ALMA-IMF XVI: Mass-averaged temperature of cores and protostellar luminosities in the ALMA-IMF protoclusters
• Will ALMA Reveal the True Core Mass Function of 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
• Simulated observations of star formation regions: infrared evolution of globally collapsing clouds
• Benchmarking the IRDC G351.77-0.53: Gaia DR3 distance, mass distribution, and star formation content
• The evolution of the internal structure of massive star forming regions in the Milky Way as revealed by ALMA
• Emergence of high-mass stars in complex fiber networks (EMERGE) II. The need for data combination in ALMA observations
• Dual-band Unified Exploration of Three CMZ Clouds (DUET). Cloud-wide census of continuum sources showing low spectral indices
• Massive extended streamers feed high-mass young stars
• ALMAGAL VI. The spatial distribution of dense cores during the evolution of cluster-forming massive clump
• The Rosetta Stone Project. II. The correlation between star formation efficiency and L/M indicator for the evolutionary stages of star-forming clumps in post-processed radiative magnetohydrodynamics simulations
• 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
• Turbulent Pressure Heats Gas and Suppresses Star Formation in Galactic Bar Molecular Clouds
• Binary Formation in a 100 $\mu$m-dark Massive Core
• Evolutionary models for the Very Massive Stars in the R136 cluster of 30 Doradus in the Large Magellanic Cloud
• The JCMT Gould Belt Survey Complete Core Catalogue: Core mass function variations between nearby molecular clouds
• Synthetic ngVLA line observations of a massive star-forming cloud
• The Evolutionary Path of Star-Forming Clumps in Hi-GAL
• Centrally concentrated star formation in young clusters
• The interdependence between density PDF, CMF and IMF and their relation with Mach number in simulations
• The dominance of turbulence over magnetism in the formation of massive star cluster seeds
• The fragmentation properties of massive star-forming regions in 30Dor-10 at 2000 au resolution
• ALMA-IMF VIII -- Combination of Interferometric Continuum Images with Single-Dish Surveys and Structural Analysis of Six Protoclusters