A High Spatial Resolution Study of the λ=3 mm Continuum of Orion-KL

Abstract

Recent interferometric observations have called into question the traditional view of the Orion-KL region, which displays one of the most well-defined cases of chemical differentiation in a star-forming region. Previous, lower-resolution images of Orion-KL show emission signatures for oxygen-bearing organic molecules toward the Orion Compact Ridge, and emission for nitrogen-bearing organic molecules toward the Orion Hot Core. However, more recent observations at higher spatial resolution indicate that the bulk of the molecular emission is arising from many smaller, compact clumps that are spatially distinct from the traditional Hot Core and Compact Ridge sources. It is this type of observational information that is critical for guiding astrochemical models, as the spatial distribution of molecules and their relation to energetic sources will govern the chemical mechanisms at play in star-forming regions. We have conducted millimeter imaging studies of Orion-KL with various beam sizes using CARMA in order to investigate the continuum structure. These λ;=3mm observations have synthesized beam sizes of ~0.5"-5.0". These observations reveal the complex continuum structure of this region, which stands in sharp contrast to the previous structural models assumed for Orion-KL based on lower spatial resolution images. The new results indicate that the spatial scaling previously used in determination of molecular abundances for this region are in need of complete revision. Here we present the results of the continuum observations, discuss the sizes and structures of the detected sources, and suggest an observational strategy for determining the proper spatial scaling to accurately determine molecular abundances in the Orion-KL region.

20 pages, 5 figures, accepted for publication in the Astrophysical Journal

References in corpus (4)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• The distance to the Orion Nebula
• Proplyds and Massive Disks in the Orion Nebula Cluster Imaged with CARMA and SMA
• Hubble Space Telescope NICMOS Polarization Measurements of OMC-1

Cited by in corpus (13)

• Antifreeze in the hot core of Orion - First detection of ethylene glycol in Orion-KL
• Complex Organic Molecules at High Spatial Resolution Toward Orion-KL II: Kinematics
• Complex Organic Molecules at High Spatial Resolution Toward Orion-KL I: Spatial Scales
• ALMA Imaging of Millimeter/Submillimeter Continuum Emission in Orion KL
• Small Protoplanetary Disks in the Orion Nebula Cluster and OMC1 with ALMA
• ALMA observations of the archetypal "hot core" that isn't: Orion KL
• The Ionized Circumstellar Envelopes of Orion Source I and the Becklin Neugebauer Object
• The Explosion in Orion-KL as Seen by Mosaicking the Magnetic Field with ALMA
• ALMA Observation of the 658 GHz Vibrationally Excited H${}_2$O Maser in Orion KL Source I
• Mapping physical parameters in Orion KL at high spatial resolution
• A systematic survey of millimetre-wavelength flaring variability of Young Stellar Objects in the Orion Nebula Cluster
• On the Relationship between CH${}_3$OD Abundance and Temperature in the Orion KL Nebula
• CARMA $\lambda$ = 1 cm Spectral Line Survey of Orion-KL