Year: 2024
Type: article
Abstract: The stellar initial mass function (IMF) is critical to our understanding of star formation and the effects of young stars on their environment. On large scales, it enables us to use tracers such as UV or Hα emission to estimate the star formation rate of a system and interpret unresolved star clusters across the Universe. So far, there is little firm evidence of large-scale variations of the IMF, which is thus generally considered “universal”. Stars form from cores, and it is now possible to estimate core masses and compare the core mass function (CMF) with the IMF, which it presumably produces. The goal of the ALMA-IMF large programme is to measure the core mass function at high linear resolution (2700 au) in 15 typical Milky Way protoclusters spanning a mass range of 2.5 × 103 to 32.7 × 103 M⊙. In this work, we used two different core extraction algorithms to extract ≈680 gravitationally bound cores from these 15 protoclusters. We adopted a per core temperature using the temperature estimate from the point-process mapping Bayesian method (PPMAP). A power-law fit to the CMF of the sub-sample of cores above the 1.64 M⊙ completeness limit (330 cores) through the maximum likelihood estimate technique yields a slope of 1.97 ± 0.06, which is significantly flatter than the 2.35 Salpeter slope. Assuming a self-similar mapping between the CMF and the IMF, this result implies that these 15 high-mass protoclusters will generate atypical IMFs. This sample currently is the largest sample that was produced and analysed self-consistently, derived at matched physical resolution, with per core temperature estimates, and cores as massive as 150 M⊙. We provide both the raw source extraction catalogues and the catalogues listing the source size, temperature, mass, spectral indices, and so on in the 15 protoclusters.
Authors: F. Louvet, P. Sanhueza, A. Stutz, A. Men’shchikov, F. Motte, R. Galván-Madrid, S. Bontemps, Y. Pouteau, A. Ginsburg, T. Csengeri, J. Di Francesco, P. Dell’Ova, M. González, P. Didelon, J. Braine, N. Cunningham, B. Thomasson, P. Lesaffre, P. Hennebelle, M. Bonfand, A. Gusdorf, R. H. Álverez-Gutiérrez, T. Nony, G. Busquet, F. Olguin, L. Bronfman, J. Salinas, M. Fernandez-Lopez, E. Moraux, H. L. Liu, X. Lu, V. Huei-Ru, A. Towner, M. Valeille-Manet, N. Brouillet, F. Herpin, B. Lefloch, T. Baug, L. Maud, A. López-Sepulcre, B. Svoboda
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, National Radio Astronomy Observatory, European Commission, Agence Nationale de la Recherche, Nuclear Safety and Security Commission, Korea Astronomy and Space Science Institute, Université de Bordeaux, National Astronomical Observatory of Japan, Agencia Nacional de Investigación y Desarrollo, Japan Society for the Promotion of Science, National Institutes of Natural Sciences, Agencia Estatal de Investigación, S. N. Bose National Centre for Basic Sciences, Astrophysics Division, H2020 European Research Council
Awards: Constraining the Origin of Stellar Masses in Hierarchical Infalling Clouds, Dynamical and chemical modeling of low-mass star-forming cores, G2262748287, G2340603345, G2428672771, G2494131340, G2848301204, G3480869486, HIGH-MASS STAR-FORMING SOURCES KNOWN AS 'HOT CORES' ARE CHARACTERIZED BY RICH MM/SUB-MM MOLECULAR EMISSION SPECTRA WITH EXCITATION TEMPERATURES TYPICALLY RANGING FROM ~100-300 K. MANY OF THE MOST COMPLEX ORGANIC MOLECULES YET DETECTED IN THE ISM ARE FOUND IN HOT CORES INCLUDING ACIDS AMINES ALCOHOLS AND ALDEHYDES. PRODUCTION OF THESE MOLECULES IS UNDERSTOOD TO BEGIN IN THE FORMATION OF SIMPLE DUST-GRAIN ICES WHICH ARE FURTHER PROCESSED AND DESORBED AS A RESULT OF THE PHYSICAL CHANGES ASSOCIATED WITH THE STAR-FORMATION PROCESS. WHILE THE CENTRAL HOT-CORE REGION IS OFTEN UNRESOLVED THE BRIGHTNESS OF THESE SOURCES AND THE HIGH MOLECULAR COLUMN DENSITIES FOUND WITHIN THEM ALLOW A GREATER RANGE OF MOLECULES TO BE DETECTED THAN TOWARD ANY OTHER TYPE OF SOURCE. HOT CORES THEREFORE PROVIDE A UNIQUE WINDOW INTO THE COMPLEX ORGANIC CHEMISTRY OF THE INTERSTELLAR MEDIUM AND OFFER THE MOST STRINGENT TESTING GROUND FOR THEORIES OF INTERSTELLAR ORGANIC MOLECULE PRODUCTION. HOWEVER WHILE MODELS OF HOT-CORE CHEMISTRY HAVE ADVANCED OVER THE PAST FEW YEARS TO MATCH THE INCREASINGLY LARGE FAMILY OF DETECTED INTERSTELLAR MOLECULES PHYSICAL TREATMENTS OF THE HOT-CORE STAGE REMAIN SIMPLISTIC USING ONLY BASIC APPROXIMATIONS TO THE IN FALL AND WARM-UP OF MATERIAL FROM THE ENVELOPE ONTO THE CENTRAL SOURCE. THIS HAS TWO MAIN CONSEQUENCES: (I) THE INFLUENCE OF TEMPERATURE DENSITY AND RADIATION FIELD ON THE ICE AND GAS-PHASE CHEMISTRY DURING IN FALL IS POORLY REPRESENTED; (II) SIMULATIONS OF THE SPECTRAL EMISSION FROM HOT CORES CANNOT TAKE ACCURATE ACCOUNT OF SOURCE STRUCTURE. THE FACT THAT THE CENTRAL HOT-CORE REGION IS USUALLY UNRESOLVED MEANS THAT THE STRUCTURE OF THE MAIN EMISSION REGION CANNOT BE OBSERVATIONALLY DETERMINED. FURTHERMORE THE USE OF OBSERVATIONAL PHYSICAL PROFILES OF THE EXTENDED ENVELOPES OF HOT-CORES TO DETERMINE THE PHYSICAL CONDITIONS FOR PARCELS OF GAS AT EARLIER STAGES OF IN FALL PROVIDES ONLY A SNAPSHOT OF PRESENT CONDITIONS WHICH MAY NOT BE INDICATIVE OF THE PHYSICAL HISTORIES OF CURRENT HOT-CORE MATERIAL. THEY WILL COMBINE STATE-OF-THE-ART HYDRODYNAMICS CHEMICAL KINETICS AND SPECTROSCOPIC MODELS TO INVESTIGATE THE CONDITIONS OF HIGH-MASS STAR FORMATION THAT LEAD TO HOT CORES. THE HD MODELS WILL HAVE A PARTICULAR EMPHASIS ON THE PHYSICAL DEVELOPMENT AND IN FALL OF THE ENVELOPE MATERIAL THAT EVENTUALLY DEVELOPS INTO THE COMPACT HOT CORE WITH A DETAILED CONSIDERATION OF THE PROPAGATION OF RADIATION FROM THE CENTRAL SOURCE (WHICH CAN RETARD THE COLLAPSE AND HEAT UP THE DUST GRAINS UPON WHICH IMPORTANT CHEMISTRY OCCURS). TRACER PARTICLES WILL BE USED TO EXTRACT TRAJECTORIES FOR MASS-CONSERVED GAS PARCELS DURING THE ENTIRE IN FALL PROCESS PRODUCING A FINAL SIMULATED HOT CORE THAT IS WELL-SAMPLED BOTH SPATIALLY AND IN THE PHYSICAL HISTORY OF THOSE SAMPLE-POINTS. ASTROCHEMICAL MODELS WILL THEN BE APPLIED TO EACH TRAJECTORY ALLOWING BOTH THE PHYSICAL AND CHEMICAL HISTORY OF THE HOT CORE TO BE TRACED OVER SPACE AND TIME. FINALLY DEDICATED SPECTRAL-SIMULATION TOOLS WILL BE USED TO PREDICT ACCURATELY THE EMISSION FROM MOLECULES IN THE HOT CORE. THIS GENERIC APPROACH WILL BE APPLIED UNDER VARIED INITIAL CONDITIONS TO EXPLORE THE EFFECTS OF PROTOSTELLAR PARAMETERS SUCH AS MASS AND MAGNETIC FIELD ON THE CHEMISTRY AND SPECTRAL EMISSION OF HOT CORES. A 3D MODEL OF BINARY STAR FORMATION WILL ALSO BE PRODUCED. RESULTS WILL BE COMPARED QUANTITATIVELY AND DIRECTLY WITH OBSERVED SOURCES USING SPECTRAL SIMULATIONS. OUR COUPLED TREATMENT OF GAS AND DUST CHEMISTRY WILL ALLOW MOLECULAR OBSERVATIONS FROM INSTRUMENTS LIKE ALMA TO BE ANALYZED IN TANDEM WITH ICE DATA FROM THE UPCOMING JAMES WEBB SPACE TELESCOPE AND THE PAST SPITZER MISSION. OUR TEAM INCORPORATES LEADING EXPERTS IN THE HYDRODYNAMICS OF STAR FORMATION RADIATIVE FEEDBACK ASTROCHEMICAL MODELING AND SPECTROSCOPY. THROUGH A COMPREHENSIVE APPROACH THIS PROJECT WILL BRING MUCH-NEEDED RIGOR TO OUR UNDERSTANDING OF THE MOST CHEMICALLY-COMPLEX INTERSTELLAR SOURCES., G3681454997, Understanding our Galactic ecosystem: From the disk of the Milky Way to the formation sites of stars and planets, G4042783231, G425668148, ろう児の読話における補聴効果に関する研究, G434337789, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES, G4817773647, Opticon RadioNet Pilot, 補剛材つき板の圧縮強度に関する研究, G5569994700, Determining the Origin of the Types of Stars found in Galaxies, G5834573078, G5905308874, CAREER: Mass Measurements in the Galaxy, G6671297155, TOWARD A PHYSICALLY-BASED UNDERSTANDING OF STAR CLUSTER FORMATION IN MILKY WAY CLOUDS CUSP OF A DATA-DRIVEN REVOLUTION, G7091402772, 古代説話における諸寺縁起の研究, MAGnetic fIeld and Kinematic coupling for massive STAR formation, GENeration and Evolution of Structures in the ISm, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA)
OpenAlex ID: W6959501722
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