Imaging the Ionized Disk of the High-Mass Protostar Orion-I

Abstract

We have imaged the enigmatic radio source-I (Orion-I) in the Orion-KL nebula with the VLA at 43 GHz with 34 mas angular resolution. The continuum emission is highly elongated and is consistent with that expected from a nearly edge-on disk. The high brightness and lack of strong molecular lines from Orion-I can be used to argue against emission from dust. Collisional ionization and H-minus free-free opacity, as in Mira variables, require a central star with >10^5 Lsun, which is greater than infrared observations allow. However, if significant local heating associated with accretion occurs, lower total luminosities are possible. Alternatively, photo-ionization from an early B-type star and p+/e- bremsstrahlung can explain our observations, and Orion-I may be an example of ionized accretion disk surrounding a forming massive star. Such accretion disks may not be able to form planets efficiently.

arXiv comment16 pages, 1 table, 3 figures

References in corpus (11)

• The Formation of Massive Stars by Accretion Through Trapped Hypercompact HII Regions
• Observations on the Formation of Massive Stars by Accretion
• Coexisting conical bipolar and equatorial outflows from a high-mass protostar
• Dynamical decay of a massive multiple system in Orion KL?
• Very compact radio emission from high-mass protostars. II. Dust disks and ionized accretion flows
• A new mid-infrared map of the BN/KL region using the Keck telescope
• High Angular Resolution Mid-infrared Imaging of Young Stars in Orion BN/KL
• Submillimeter Array 440$\mu$m/690GHz line and continuum observations of Orion-KL
• Very compact radio emission from high-mass protostars. I. CRL 2136: Continuum and water maser observations
• Wide-Angle Wind Driven Bipolar Outflows: High Resolution Models with Application to Source I of the Becklin-Neugebauer / Kleinmann-Low OMC-I Region
• OH maser disc and outflow in the Orion-BN/KL region

Cited by in corpus (57)

• The distance to the Orion Nebula
• Disk-Driven Rotating Bipolar Outflow in Orion Source I
• Radio Jets from Young Stellar Objects
• A Feature Movie of SiO Emission 20-100 AU from the Massive Young Stellar Object Orion Source I
• Explosive Outflows Powered by the Decay of Non-Hierarchical Multiple Systems of Massive Stars: Orion BN/KL
• Monitoring the Large Proper Motions of Radio Sources in the Orion BN/KL Region
• The ALMA View of the OMC1 Explosion in Orion
• Evolution of Magnetic Fields in High Mass Star Formation: Linking field geometry and collapse for the W51 e2/e8 cores
• A Multi-Epoch Study of the Radio Continuum Emission of Orion Source I: Constraints on the Disk Evolution of a Massive YSO and the Dynamical History of Orion BN/KL
• A Keplerian disk around Orion Source I, a ~15 Msun YSO
• Orion KL: The hot core that is not a "Hot Core"
• Weak and Compact Radio Emission in Early High-Mass Star Forming Regions: I. VLA Observations
• Unveiling Sources of Heating in the Vicinity of the Orion BN/KL Hot Core as Traced by Highly Excited Inversion Transitions of Ammonia
• High-Angular Resolution Dust Polarization Measurements: Shaped B-field Lines in the Massive Star Forming Region Orion BN/KL
• A ring/disk/outflow system associated with W51 North: a very massive star in the making
• Maser emission from SiO isotopologues traces the innermost 100 AU around Radio Source I in Orion BN/KL
• Herschel Far-Infrared Spectral-mapping of Orion BN/KL Outflows: Spatial distribution of excited CO, H2O, OH, O and C+ in shocked gas
• An Extensive, Sensitive Search for SiO Masers in High- and Intermediate-Mass Star-Forming Regions
• ALMA Observations of Orion Source I at 350 and 660 GHz
• Dynamical Evidence for a Magnetocentrifugal Wind from a 20 Msun Binary Young Stellar Object
• Hot Molecular Circumstellar Disk around Massive Protostar Orion Source I
• The near-infrared reflected spectrum of source I in Orion-KL
• Identifying the outflow driving sources in Orion-KL
• A 1.3 cm wavelength radio flare from a deeply embedded source in the Orion BN/KL region
• ALMA observations of the outflow from the Source I in the Orion-KL region
• Resolving the Structure and Kinematics of the BN Object at $0\text{.}"2$ Resolution
• High-resolution EVLA image of dimethyl ether (CH${}_3$)${}_2$O in Orion--KL
• ALMA Imaging of Millimeter/Submillimeter Continuum Emission in Orion KL
• The first detection of the 232 GHz vibrationally excited H2O maser in Orion KL with ALMA
• OMC-1 dust polarisation in ALMA Band 7: Diagnosing grain alignment mechanisms in the vicinity of Orion Source I
• Protostellar Outflows at the EarliesT Stages (POETS). III. H2O masers tracing disk-winds and jets near luminous YSOs
• Short- and long-term variability of young stars in the Orion Nebula Cluster and Molecular Cloud
• VLBA imaging of the 3mm SiO maser emission in the disk-wind from the massive protostellar system Orion Source I
• A study of dynamical processes in the Orion KL region using ALMA-- Probing molecular outflow and inflow
• Outflow Structure and Velocity Field of Orion Source I: ALMA Imaging of SiO Isotopologue Maser and Thermal Emission
• Physical Relation of Source I to IRc2 in the Orion KL Region
• The Ionized Circumstellar Envelopes of Orion Source I and the Becklin Neugebauer Object
• Probing the envelopes of massive young stellar objects with diffraction limited mid-infrared imaging
• A differentially rotating disc in a high-mass protostellar system
• Mid-J CO emission from the Orion BN/KL explosive outflow
• ALMA and VLA observations of recombination lines and continuum toward the Becklin-Neugebauer object in Orion
• Intermittent maser flare around the high mass young stellar object G353.273+0.641 II: Detection of a radio and molecular jet
• Circumbinary disc survival during binary-single scattering: towards a dynamical model of the Orion BN/KL complex
• Observations of Orion Source I Disk and Outflow Interface
• Magnetic Field Structure of Orion Source I
• ALMA Observation of the 658 GHz Vibrationally Excited H${}_2$O Maser in Orion KL Source I
• Outflow-Confined HII regions. II. The Early Break-Out Phase
• ALMA observations and modeling of the rotating outflow in Orion Source I
• MHD Modeling of a Disk-Wind from a High-Mass Protobinary: the case of Orion Source I
• ALMA band 8 continuum emission from Orion Source I
• Structure of the Source I disk in Orion-KL
• The Science Case for Simultaneous mm-Wavelength Receivers in Radio Astronomy
• Keck Adaptive Optics Observations of the Protostellar Disk around Radio Source I in the Orion Kleinmann-Low Nebula
• Extremely high excitation SiO lines in disk-outflow system in Orion Source I
• An ionized outflow in Orion-KL source I?
• Probing the fast outflow in IRAS 15452-5459 with ATCA observations of OH, H2O, and SiO masers
• Synthetic Polarization Maps of an Outflow Zone from Magnetohydrodynamic Simulations