High-mass Star Formation through Filamentary Collapse and Clump-fed Accretion in G22

Abstract

How mass is accumulated from cloud-scale down to individual stars is a key open question in understanding high-mass star formation. Here, we present the mass accumulation process in a hub-filament cloud G22 which is composed of four supercritical filaments. Velocity gradients detected along three filaments indicate that they are collapsing with a total mass infall rate of about 440 $M_{\odot }$ Myr${}^{-1}$, suggesting the hub mass would be doubled in six free-fall times, adding up to $\sim 2$ Myr. A fraction of the masses in the central clumps C1 and C2 can be accounted for through large-scale filamentary collapse. Ubiquitous blue profiles in HCO${}^{+}$ $(3-2)$ and ${}^{13}$CO $(3-2)$ spectra suggest a clump-scale collapse scenario in the most massive and densest clump C1. The estimated infall velocity and mass infall rate are 0.31 km s${}^{-1}$ and $7.2\times 10^{-4}$ $M_{\odot }$ yr${}^{-1}$, respectively. In clump C1, a hot molecular core (SMA1) is revealed by the SMA observations and an outflow-driving high-mass protostar is located at the center of SMA1. The mass of the protostar is estimated to be $11-15$ $M_{\odot }$ and it is still growing with an accretion rate of $7\times 10^{-5}$ $M_{\odot }$ yr${}^{-1}$. The coexistent infall in filaments, clump C1, and the central hot core in G22 suggests that pre-assembled mass reservoirs (i.e., high-mass starless cores) may not be required to form high-mass stars. In the course of high-mass star formation, the central protostar, the core, and the clump can simultaneously grow in mass via core-fed/disk accretion, clump-fed accretion, and filamentary/cloud collapse.

17 pages, 16 figures 3 tables. and Accepted for publication in ApJ

References in corpus (18)

• The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive Forcing
• A Catalog of Extended Green Objects (EGOs) in the GLIMPSE Survey: A new sample of massive young stellar object outflow candidates
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• Circumventing the radiation pressure barrier in the formation of massive stars via disk accretion
• On the Density Distribution in Star-forming Interstellar Clouds
• A Class I and Class II Methanol Maser Survey of Extended Green Objects (EGOs) from the GLIMPSE Survey
• Intrinsically Red Sources observed by Spitzer in the Galactic Mid-Plane
• Three-dimensional simulation of massive star formation in the disk accretion scenario
• Large-scale filaments associated with Milky Way spiral arms
• Understanding star formation in molecular clouds I. Effects of line-of-sight contamination on the column density structure
• Understanding star formation in molecular clouds II. Signatures of gravitational collapse of IRDCs
• A Census of Large-Scale ($\ge$ 10 pc), Velocity-Coherent, Dense Filaments in the Northern Galactic Plane: Automated Identification Using Minimum Spanning Tree
• Subarcsecond Imaging of the NGC 6334 I(N) Protocluster: Two Dozen Compact Sources and a Massive Disk Candidate
• L1188: a promising candidate of cloud-cloud collision triggering the formation of the low- and intermediate-mass stars
• A study of dynamical processes in the Orion KL region using ALMA-- Probing molecular outflow and inflow
• The inflow signature toward different evolutionary phases of massive star formation

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• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions-IX. A pilot study towards IRDC G034.43+00.24 on multi-scale structures and gas kinematics
• ALMA observations reveal no preferred outflow--filament and outflow--magnetic field orientations
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): I. Detection of New Hot Corinos with ACA
• Physical and chemical structure of the Serpens filament -- fast formation and gravity-driven accretion
• Kinematics and star formation toward W33: a central hub as a hub--filament system
• TRAO Survey of the nearby filamentary molecular clouds, the universal nursery of stars (TRAO FUNS). II. Filaments and Dense cores in IC 5146
• TRAO Survey of Nearby Filamentary Molecular clouds, the Universal Nursery of Stars (TRAO FUNS) I. Dynamics and Chemistry of L1478 in the California Molecular Cloud
• Initial phases of high-mass star formation: A multiwavelength study towards the extended green object G12.42+0.50
• Role of Filamentary Structures in the Formation of Two Dense Cores, L1544 and L694-2
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• VLA ammonia observations of L1287: analysis of the "Guitar" core and two filaments
• A Catalog of Molecular Clumps and Cores with Infall Signatures
• Gas Kinematics of the Massive Protocluster G286.21+0.17 Revealed by ALMA
• Star formation in IRDC G31.97+0.07
• Sequential Star Formation in the filamentary structures of Planck Galactic cold clump G181.84+0.31
• Investigating the physical conditions in extended system hosting mid-infrared bubble N14