Core fragmentation and Toomre stability analysis of W3(H2O): A case study of the IRAM NOEMA large program CORE

Abstract

The fragmentation mode of high-mass molecular clumps and the properties of the central rotating structures surrounding the most luminous objects have yet to be comprehensively characterised. Using the IRAM NOrthern Extended Millimeter Array (NOEMA) and the IRAM 30-m telescope, the CORE survey has obtained high-resolution observations of 20 well-known highly luminous star-forming regions in the 1.37 mm wavelength regime in both line and dust continuum emission. We present the spectral line setup of the CORE survey and a case study for W3(H2O). At ~0.35" (700 AU at 2 kpc) resolution, the W3(H2O) clump fragments into two cores (West and East), separated by ~2300 AU. Velocity shifts of a few km/s are observed in the dense-gas tracer, CH3CN, across both cores, consistent with rotation and perpendicular to the directions of two bipolar outflows, one emanating from each core. The kinematics of the rotating structure about W3(H2O) W shows signs of differential rotation of material, possibly in a disk-like object. The observed rotational signature around W3(H2O) E may be due to a disk-like object, an unresolved binary (or multiple) system, or a combination of both. We fit the emission of CH3CN (12-11) K = 4-6 and derive a gas temperature map with a median temperature of ~165 K across W3(H2O). We create a Toomre Q map to study the stability of the rotating structures against gravitational instability. The rotating structures appear to be Toomre unstable close to their outer boundaries, with a possibility of further fragmentation in the differentially-rotating core W3(H2O) W. Rapid cooling in the Toomre-unstable regions supports the fragmentation scenario. Combining millimeter dust continuum and spectral line data toward the famous high-mass star-forming region W3(H2O), we identify core fragmentation on large scales, and indications for possible disk fragmentation on smaller spatial scales.

arXiv comment23 pages, 26 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (48)

• A new calibration of stellar parameters of Galactic O stars
• Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks
• ATLASGAL - The APEX Telescope Large Area Survey of the Galaxy at 870 microns
• Physical Conditions in Regions of Star Formation
• The Formation of Massive Star Systems by Accretion
• Gravitational Instabilities in Circumstellar Disks
• High-Mass Star and Massive Cluster Formation in the Milky Way
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• On the formation of massive stars
• The Distance to the Perseus Spiral Arm in the Milky Way
• Circumventing the radiation pressure barrier in the formation of massive stars via disk accretion
• H II regions: Witnesses to massive star formation
• Three-dimensional simulation of massive star formation in the disk accretion scenario
• Water maser motions in W3(OH) and a determination of its distance
• Fragmentation and mass segregation in the massive dense cores of Cygnus X
• IRAS 05358+3543: Multiple outflows at the earliest stages of massive star formation
• Nonlinear Outcome of Gravitational Instability in Disks with Realistic Cooling
• Accretion disks in luminous young stellar objects
• Formation of massive stars by growing accretion rate
• The RMS Survey: Critical Tests of Accretion Models for the Formation of Massive Stars
• A distance limited sample of massive molecular outflows
• Fragmentation of a Molecular Cloud Core versus Fragmentation of the Massive Protoplanetary Disk in the Main Accretion Phase
• 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
• A Keplerian-like disk around the forming O-type star AFGL 4176
• eXtended CASA Line Analysis Software Suite (XCLASS)
• Hot gas and dust in a protostellar cluster near W3(OH
• Observations on the Formation of Massive Stars by Accretion
• A candidate circumbinary Keplerian disk in G35.20-0.74 N: A study with ALMA
• G11.92-0.61 MM1: A Keplerian disc around a massive young proto-O star
• Gravity or turbulence? -III. Evidence of pure thermal Jeans fragmentation at ~0.1 pc scale
• The RMS Survey: The Bolometric Fluxes and Luminosity Distributions of Young Massive Stars
• Early stages of cluster formation: fragmentation of massive dense cores down to ~1000 AU
• Forming spectroscopic massive proto-binaries by disk fragmentation
• Simulating the Formation of Massive Protostars: I. Radiative Feedback and Accretion Disks
• Complex Structure in Class 0 Protostellar Envelopes III: Velocity Gradients in Non-Axisymmetric Envelopes, Infall or Rotation?
• On the simultaneous evolution of massive protostars and their host cores
• Testing the massive disk scenario for IRAS 18089-1732
• The fragmentation criteria in local vertically stratified self-gravitating disk simulations
• Resolving the Circumstellar Disk Around the Massive Protostar Driving the HH 80-81 Jet
• A Hot and Massive Accretion Disk around the High-Mass Protostar IRAS 20126+4104
• On the kinematics of massive star forming regions: the case of IRAS 17233-3606
• A High-Mass Protobinary System in the Hot Core W3(H2O)
• SMA Observations of W3(OH) Complex: Physical and Chemical Differentiation between W3(H${}_2$O) and W3(OH)
• Rotational Structure and Outflow in the Infrared Dark Cloud 18223-3
• Disks and outflows in the massive protobinary system W3(OH)TW
• The 10^5Lsun High-Mass Protostellar Object IRAS23151+5912
• Synchrotron emission from circumstellar disks around massive stars

Cited by in corpus (33)

• G11.92-0.61 MM 1: A fragmented Keplerian disk surrounding a proto-O star
• Substructures in the Keplerian disc around the O-type (proto)star G17.64+0.16
• Formation and Evolution of Disks around Young Stellar Objects
• Does the magnetic field suppress fragmentation in massive dense cores?
• Chasing discs around O-type (proto)stars - ALMA evidence for an SiO disc and disc wind from G17.64+0.16
• Chemical complexity in high-mass star formation: An observational and modeling case study of the AFGL 2591 VLA 3 hot core
• Spiral arms and instability within the AFGL 4176 mm1 disc
• Collapse of turbulent massive cores with ambipolar diffusion and hybrid radiative transfer I. Accretion and multiplicity
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- VIII. A search for hot cores by using C${}_2$H${}_5$CN, CH${}_3$OCHO and CH${}_3$OH lines
• The first bird's-eye view of a gravitationally unstable accretion disk in high-mass star formation
• Disk Kinematics and Stability in High-Mass Star Formation: Linking Simulations and Observations
• Parameter study for the burst mode of accretion in massive star formation
• Multi-scale view of star formation in IRAS 21078+5211: From clump fragmentation to disk wind
• Kinematics and stability of high-mass protostellar disk candidates at sub-arcsecond resolution -- Insights from the IRAM NOEMA large program CORE
• IRAS23385+6053: An embedded massive cluster in the making
• A Detailed View of the Circumstellar Environment and Disk of the Forming O-star AFGL 4176
• Fragmentation, rotation and outflows in the high-mass star-forming region IRAS 23033+5951. A case study of the IRAM NOEMA large program CORE
• Sulfur-bearing molecules in Orion KL
• On the ALMA observability of nascent massive multiple systems formed by gravitational instability
• JOYS: Disentangling the warm and cold material in the high-mass IRAS 23385+6053 cluster
• Disk fragmentation in high-mass star formation. High-resolution observations towards AFGL 2591-VLA 3
• Physical conditions in the warped accretion disk of a massive star. 349 GHz ALMA observations of G023.01$-$00.41
• Mixing of materials in magnetised core-collapse supernova remnants
• The burst mode of accretion in massive star formation with stellar inertia
• Multi-wavelength modelling of the circumstellar environment of the massive proto-star AFGL 2591 VLA 3
• The Detection of Deuterated Water in the Large Magellanic Cloud with ALMA
• The physical and chemical structure of high-mass star-forming regions. Unraveling chemical complexity with the NOEMA large program "CORE"
• Redshifted methanol absorption tracing infall motions of high-mass star formation regions
• A new phase of massive star formation? A luminous outflow cavity centred on an infrared quiet core
• Mapping Physical Conditions in Neighboring Hot Cores: NOEMA Studies of W3(H${}_2$O) and W3(OH)
• Comparing Complex Chemistry in Neighboring Hot Cores: NOEMA Studies of W3(H${}_2$O) and W3(OH)
• Discs and outflows in the early phases of massive star formation: influence of magnetic fields and ambipolar diffusion
• First Trigonometric Parallax Measurements with the KVN and VERA Array (KaVA)