ALMA band 8 continuum emission from Orion Source I

Abstract

We have measured continuum flux densities of a high-mass protostar candidate, a radio source I in the Orion KL region (Orion Source I) using the Atacama Large Millimeter/Submillimeter Array (ALMA) at band 8 with an angular resolution of 0.1". The continuum emission at 430, 460, and 490 GHz associated with Source I shows an elongated structure along the northwest-southeast direction perpendicular to the so-called low-velocity bipolar outflow. The deconvolved size of the continuum source, 90 au times 20 au, is consistent with those reported previously at other millimeter/submillimeter wavelength. The flux density can be well fitted to the optically thick black-body spectral energy distribution (SED), and the brightness temperature is evaluated to be 700-800 K. It is much lower than that in the case of proton-electron or H- free-free radiations. Our data are consistent with the latest ALMA results by Plambeck & Wright (2016), in which the continuum emission have been proposed to arise from the edge-on circumstellar disk via thermal dust emission, unless the continuum source consists of an unresolved structure with the smaller beam filling factor.

arXiv comment5 pages, 2 figures, accepted for publication in the The Astrophysical Journal

References in corpus (20)

• The distance to the Orion Nebula
• A Feature Movie of SiO Emission 20-100 AU from the Massive Young Stellar Object Orion Source I
• 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
• Tracing the Bipolar Outflow from Orion Source I
• Imaging the Ionized Disk of the High-Mass Protostar Orion-I
• Compact Radio Sources in Orion: New Detections, Time Variability, and Objects in OMC-1S
• Sub-arcsecond sub-mm continuum observations of Orion-KL
• Submillimeter Array 440$\mu$m/690GHz line and continuum observations of Orion-KL
• An Extensive, Sensitive Search for SiO Masers in High- and Intermediate-Mass Star-Forming Regions
• The Population of Compact Radio Sources in the Orion Nebula Cluster
• Dynamical Evidence for a Magnetocentrifugal Wind from a 20 Msun Binary Young Stellar Object
• ALMA Observations of Orion Source I at 350 and 660 GHz
• Hot Molecular Circumstellar Disk around Massive Protostar Orion Source I
• ALMA observations of the outflow from the Source I in the Orion-KL region
• 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
• Short- and long-term variability of young stars in the Orion Nebula Cluster and Molecular Cloud
• Outflow Structure and Velocity Field of Orion Source I: ALMA Imaging of SiO Isotopologue Maser and Thermal Emission
• The Ionized Circumstellar Envelopes of Orion Source I and the Becklin Neugebauer Object
• ALMA Observation of the 658 GHz Vibrationally Excited H${}_2$O Maser in Orion KL Source I

Cited by in corpus (8)

• Disk-Driven Rotating Bipolar Outflow in Orion Source I
• Massive Outflows Driven by Magnetic Effects II: Comparison with Observations
• ALMA Images of the Orion Hot Core at 349 GHz
• ALMA observations of the archetypal "hot core" that isn't: Orion KL
• A Face-on Accretion System in High-Mass Star-Formation: Possible Dusty Infall Streams within 100 AU
• Magnetic Field Structure of Orion Source I
• Extremely high excitation SiO lines in disk-outflow system in Orion Source I
• Synthetic Polarization Maps of an Outflow Zone from Magnetohydrodynamic Simulations