The sharp ALMA view of infall and outflow in the massive protocluster G31.41+0.31

Abstract

Context. To better understand the formation of high-mass stars, it is fundamental to investigate how matter accretes onto young massive stars, how it is ejected, and how all this differs from the low-mass case. The massive protocluster G31.41+0.31 is the ideal target to study all these processes because observations at millimeter and centimeter wavelengths have resolved the emission of the Main core into at least four massive dust continuum sources, named A, B, C, and D, within 1" or 0.018 pc, and have identified signatures of infall and several outflows associated with the core. Aims. We study the interplay between infall and outflow in G31.41+0.31 by investigating at a spatial resolution of a few 100 au their properties and their possible impact on the core. Methods. We carried out molecular line observations of typical high-density tracers, such as CH3CN or H2CO, and shock and outflow tracers, such as SiO, with ALMA at 1.4 mm that achieved an angular resolution of 0.09" (340 au). Results. The observations have revealed inverse P-Cygni profiles in CH3CN and H2CO toward the four sources embedded in the Main core, suggesting that all of them are undergoing collapse. The infall rates, estimated from the red-shifted absorption are on the order of 1E-2 Msun/yr. The individual infall rates imply that the accretion timescale of the Main core is an order of magnitude smaller than its rotation timescale. This confirms that rotating toroids such as the G31 Main core are non-equilibrium, transient collapsing structures that need to be constantly replenished with fresh material from a large-scale reservoir. For sources B, C, and D, the infall could be accelerating inside the sources, while for source A, the presence of a second emission component complicates the interpretation. The SiO observations have revealed the presence of at least six outflows in the G31.41+0.31 star-forming region, ...

arXiv comment17 pages, 9 figures, 2 tables. Accepted by A&A

References in corpus (42)

• High-Mass Star and Massive Cluster Formation in the Milky Way
• Massive molecular outflows
• The Interplay of Magnetic Fields, Fragmentation and Ionization Feedback in High-Mass Star Formation
• Complex Molecules in the L1157 Molecular Outflow
• An extraordinary outburst in the massive protostellar system NGC6334I-MM1: quadrupling of the millimeter continuum
• Accretion disks in luminous young stellar objects
• IRAS 16293-2422: proper motions, jet precession, the hot core, and the unambiguous detection of infall
• Collapse-Driven Outflow in Star-Forming Molecular Cores
• On the existence of accretion-driven bursts in massive star formation
• A detailed study of the rotating toroids in G31.41+0.31 and G24.78+0.08
• First hydrodynamics simulations of radiation forces and photoionization feedback in massive star formation
• The formation of ethylene glycol and other complex organic molecules in star-forming regions
• Rotating toroids in G10.62-0.38, G19.61-0.23, and G29.96-0.02
• Investigations of Protostellar Outflow Launching and Gas Entrainment: Hydrodynamic Simulations and Molecular Emission
• The Extraordinary Outburst in the Massive Protostellar System NGC6334I-MM1: Emergence of Strong 6.7 GHz Methanol Masers
• Bipolar jets launched from magnetically diffusive accretion disks. I. Ejection efficiency vs field strength and diffusivity
• Very Massive Stars in the Local Universe
• STATCONT: A statistical continuum level determination method for line-rich sources
• Modeling disk fragmentation and multiplicity in massive star formation
• Accelerating infall and rotational spin-up in the hot molecular core G31.41+0.31
• Multi-directional mass-accretion and collimated outflows in W51
• Terahertz ammonia absorption as a probe of infall in high-mass star forming clumps
• ALMA resolves the hourglass magnetic field in G31.41+0.31
• Collapsing Hot Molecular Cores: A Model for the Dust Spectrum and Ammonia Line Emission of the G31.41+0.31 Hot Core
• Dissecting a hot molecular core: The case of G31.41+0.31
• Burst occurrence in young massive stellar objects
• Chemical complexity in high-mass star formation: An observational and modeling case study of the AFGL 2591 VLA 3 hot core
• The Formation of Very Massive Stars
• Molecular outflows and hot molecular core in G24.78+0.08 at sub-arcsecond angular resolution
• Anomalous peculiar motions of high-mass young stars in the Scutum spiral arm
• Molecular CO outflows in the L1641-N cluster: kneading a cloud core
• SiO collimated outflows driven by high-mass YSOs in G24.78+0.08
• The Extraordinary Outburst in the Massive Protostellar System NGC6334I-MM1: Strong Increase in Mid-Infrared Continuum Emission
• Tracing jet emission at the base of a high-mass YSO. First AMBER/VLTI observations of the Brγemission in IRAS 13481-6124
• A Double-Jet System in the G31.41+0.31 Hot Molecular Core
• X-ray embedded stars as driving sources of outflow-driven turbulence in OMC1-S
• Fragmentation in the massive G31.41+0.31 protocluster
• Centrifugally driven winds from protostellar accretion discs. I - Formulation and initial results
• The mass of dusty clumps with temperature and density structure
• The ionized heart of a molecular disk. ALMA observations of the hyper-compact HII region G24.78+0.08 A1
• Multi-line Herschel/HIFI observations of water reveal infall motions and chemical segregation around high-mass protostars
• Disks around O-type young stellar objects

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• The evolution of the internal structure of massive star forming regions in the Milky Way as revealed by ALMA
• Massive extended streamers feed high-mass young stars
• The GUAPOS project. VI: the chemical inventory of shocked gas
• ALMA and VLBA views on the outflow associated with an O-type protostar in G26.50+0.28
• A multi-scale view of the magnetic field morphology in the hot molecular core G31.41+0.31
• ATLASGAL-selected high-mass clumps in the inner Galaxy: XI. Morphology and kinematics of warm inner envelopes
• Surveys of clumps, cores, and condensations in Cygnus-X: Searching for Keplerian disks on the scale of 500 au
• NH3 (1,1) hyperfine intensity anomalies in infall sources
• The GUAPOS project -- VII: Physical structure and molecular environment of the G31.41+0.31 HII region