Observations on the Formation of Massive Stars by Accretion

Abstract

Observations of the H66a recombination line from the ionized gas in the cluster of newly formed massive stars, G10.6-0.4, show that most of the continuum emission derives from the dense gas in an ionized accretion flow that forms an ionized disk or torus around a group of stars in the center of the cluster. The inward motion observed in the accretion flow suggests that despite the equivalent luminosity and ionizing radiation of several O stars, neither radiation pressure nor thermal pressure has reversed the accretion flow. The observations indicate why the radiation pressure of the stars and the thermal pressure of the HII region are not effective in reversing the accretion flow. The observed rate of the accretion flow, 0.001 solar masses/yr, is sufficient to form massive stars within the time scale imposed by their short main sequence lifetimes. A simple model of disk accretion relates quenched HII regions, trapped hypercompact HII regions, and photo-evaporating disks in an evolutionary sequence.

References in corpus (12)

• Massive molecular outflows
• The Formation of Massive Stars by Accretion Through Trapped Hypercompact HII Regions
• Ionizing Photon Emission Rates from O- and Early B-type Stars and Clusters
• Formation of massive stars by growing accretion rate
• Infall Collapse Solutions in the Inner Limit: Radiation Pressure and its Effects on Star Formation
• Rotating disks in high-mass young stellar objects
• Spherical Infall in G10.6-0.4: Accretion Through an Ultracompact HII Region
• Very compact radio emission from high-mass protostars. II. Dust disks and ionized accretion flows
• Clumpy Ultracompact HII Regions I: Fully Supersonic Wind-blown Models
• A 3D Monte Carlo Photoionization Code for Modeling Diffuse Ionized Gas
• NGC7538S - a High-Mass Protostar with a Massive Rotating Disk
• Radiative Transfer Modelling of the Accretion Flow onto a Star-Forming Core in W51

Cited by in corpus (90)

• Theory of Star Formation
• Toward Understanding Massive Star Formation
• Evolution of Massive Protostars with High Accretion Rates
• H II regions: Witnesses to massive star formation
• The Interplay of Magnetic Fields, Fragmentation and Ionization Feedback in High-Mass Star Formation
• Interstellar OH+, H2O+ and H3O+ along the sight-line to G10.6-0.4
• Unifying low and high mass star formation through density amplified hubs of filaments
• The formation of massive stars: accretion, disks and the development of hypercompact HII regions
• Probing the initial conditions of high-mass star formation. II. Fragmentation, stability, and chemistry
• Understanding Spatial and Spectral Morphologies of Ultracompact H II Regions
• Far-Infrared Dust Temperatures and Column Densities of the MALT90 Molecular Clump Sample
• From the Convergence of Filaments to Disk-Outflow Accretion: Massive-Star Formation in W33A
• The Early Evolution of Massive Stars: Radio Recombination Line Spectra
• A near IR imaging survey of intermediate and high-mass young stellar outflow candidates
• Rotating toroids in G10.62-0.38, G19.61-0.23, and G29.96-0.02
• Forming spectroscopic massive proto-binaries by disk fragmentation
• Outflow and Infall in a Sample of Massive Star Forming Regions
• The Youngest Stellar clusters Clusters associated with massive protostellar candidates
• Imaging the Ionized Disk of the High-Mass Protostar Orion-I
• Formation of an O-Star Cluster by Hierarchical Accretion in G20.08-0.14 N
• Molecular outflows towards O-type young stellar objects
• Thermal Feedback in the high-mass star and cluster forming region W51
• Forming an Early O-type Star Through Gas Accretion?
• Multi-directional mass-accretion and collimated outflows in W51
• The standard model of star formation applied to massive stars: accretion disks and envelopes in molecular lines
• Evidence for feedback and stellar-dynamically regulated bursty star cluster formation: the case of the Orion Nebula Cluster
• Rotation of the Warm Molecular Gas Surrounding Ultracompact HII Regions
• Discovery of Extremely High Velocity "Molecular Bullets" in the HH 80-81 High-Mass Star-Forming Region
• The Ionization of Accretion Flows in High Mass Star Formation: W51e2
• Burst occurrence in young massive stellar objects
• Time Variation in G24.78+0.08 A1: Evidence for an Accreting Hypercompact H II Region?
• Core fragmentation and Toomre stability analysis of W3(H2O): A case study of the IRAM NOEMA large program CORE
• The Origin of OB Clusters: From 10 pc to 0.1 pc
• Low-Metallicity Protostars and the Maximum Stellar Mass Resulting from Radiative Feedback
• The initial mass function of star clusters that form in turbulent molecular clouds
• Star Formation in Molecular Clouds
• A population of hypercompact HII regions identified from young HII regions
• The high-mass disk candidates NGC7538IRS1 and NGC7538S
• The role of stellar collisions for the formation of massive stars
• The Formation of Very Massive Stars
• Kinematics of a hot massive accretion disk candidate
• Extremely large and hot multilayer Keplerian disk around the O-type protostar W51N: The precursors of the HCHII regions?
• Slow ionized wind and rotating disklike system associated with the high-mass young stellar object G345.4938+01.4677
• A high resolution study of complex organic molecules in hot cores
• The hyperyoung HII region in G24.78+0.08 A1
• Mass Transfer in Close, Rapidly Accreting Protobinaries: An Origin for Massive Twins?
• The evolution of young HII regions
• Evidence of Short Timescale Flux Density Variations of UC HII regions in Sgr B2 Main and North
• Evidence for Inflow in High-Mass Star-Forming Clumps
• Dynamics of a Massive Binary at Birth
• Massive pre-main sequence stars in M17
• A dearth of young and bright massive stars in the Small Magellanic Cloud
• Parameter study for the burst mode of accretion in massive star formation
• Outflow and Infall in a Sample of Massive Star Forming Regions II: Large Scale Kinematics
• On the episodic excursions of massive protostars in the Hertzsprung-Russell diagram
• Millimeter and submillimeter high angular resolution interferometric observations: dust in the heart of IRAS 18162-2048
• A Protostellar Jet Emanating from a Hypercompact HII Region
• High Velocity Molecular Outflows In Massive Cluster Forming Region G10.6-0.4
• A rotating molecular disk toward IRAS 18162-2048, the exciting source of HH 80-81
• Ionized Gas Towards Molecular Clumps: Physical Properties of Massive Star Forming Regions
• The Morphology of M17-UC1 - A Disk Candidate Surrounding a Hypercompact HII Region
• Spectral Energy Distributions of High Mass Proto Stellar Objects - Evidence for High Accretion Rates
• Circumbinary Molecular Rings Around Young Stars in Orion
• The standard model of low-mass star formation applied to massive stars: multi-wavelength modelling of IRAS 20126+4104
• On the ALMA observability of nascent massive multiple systems formed by gravitational instability
• High Resolution CO Observations of Massive Star Forming Regions
• A collimated jet and an infalling-rotating disk in G192.16-3.84 traced by H2O maser emission
• Supersonic turbulence in the cold massive core JCMT 18354-0649S
• The Youngest Globular Clusters
• Interpreting observations of edge-on gravitationally unstable accretion flows
• Ionised gas kinematics in bipolar H II regions
• Ionization driven molecular outflow in K3-50A
• Chemical evolution of N2H+ in six massive star-forming regions
• Surveys of Clumps, Cores, and Condensations in the Cygnus X: II. Radio Properties of the Massive Dense Cores
• Illuminating a tadpole's metamorphosis II: observing the on-going transformation with ALMA
• Molecular line study of massive star forming regions from the RMS survey
• The Dynamics of Ultracompact HII Regions
• Physical and chemical properties of Red MSX Sources in the southern sky: HII regions
• Massive extended streamers feed high-mass young stars
• Clustered Formation of Massive Stars within an Ionized Rotating Disk
• Physics and chemistry of hot molecular cores
• [Fe II] 1.64 um Imaging Observations of the Outflow Features around Ultracompact H II Regions in the 1st Galactic Quadrant
• Radiation hydrodynamic simulations of massive star formation via gravitationally trapped HII regions - Spherically symmetric ionised accretion flows
• Modeling High-Mass Star Formation and Ultracompact HII Regions
• Discovery of a New Population of Galactic HII Regions with Ionized Gas Velocity Gradients
• Study of the molecular and ionized gas in a possible precursor of an ultra-compact HII region
• ngVLA Synthetic Observations of Ionized Gas in Massive Protostars
• The ultracompact regions G40.54+2.59 and G34.13+0.47: A new detection of compact radio sources
• Identification of Anomalous E+A Galaxies in GAMA Using an Isolation Forest
• Time Variability in Simulated Ultracompact and Hypercompact HII Regions