The JCMT Legacy Survey of the Gould Belt: mapping 13CO and C18O in Orion A

Abstract

The Gould Belt Legacy Survey will map star-forming regions within 500 pc, using HARP (Heterodyne Array Receiver Programme), SCUBA-2 (Submillimetre Common-User Bolometer Array 2) and POL-2 (Polarimeter 2) on the James Clerk Maxwell Telescope (JCMT). This paper describes HARP observations of the J = 3-2 transitions of 13CO and C18O towards Orion A. The 1500-resolution observations cover 5 pc of the Orion filament, including OMC1 (inc. BN-KL and Orion Bar), OMC 2/3 and OMC 4, and allow a comparative study of the molecular gas properties throughout the star-forming cloud. The filament shows a velocity gradient of ~1 km/s /pc between OMC 1, 2 and 3, and high velocity emission is detected in both isotopologues. The Orion Nebula and Bar have the largest masses and line widths, and dominate the mass and energetics of the high velocity material. Compact, spatially resolved emission from CH3CN, 13CH3OH, SO, HCOOCH3, C2H5OH, CH3CHO and CH3OCHO is detected towards the Orion Hot Core. The cloud is warm, with a median excitation temperature of ~24 K; the Orion Bar has the highest excitation temperature gas, at >80 K. The C18O excitation temperature correlates well with the dust temperature (to within 40%). The C18O emission is optically thin, and the 13CO emission is marginally optically thick; despite its high mass, OMC 1 shows the lowest opacities. A virial analysis indicates that Orion A is too massive for thermal or turbulent support, but is consistent with a model of a filamentary cloud that is threaded by helical magnetic fields. The variation of physical conditions across the cloud is reflected in the physical characteristics of the dust cores....continued

Accepted by MNRAS

References in corpus (15)

• Theory of Star Formation
• From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt survey
• The distance to the Orion Nebula
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• CO Isotopologues in the Perseus Molecular Cloud Complex: the X-Factor and Regional Variations
• A SCUBA survey of Orion, the low-mass end of the core mass function
• The James Clerk Maxwell Telescope Legacy Survey of Nearby Star-forming Regions in the Gould Belt
• Explosive Outflows Powered by the Decay of Non-Hierarchical Multiple Systems of Massive Stars: Orion BN/KL
• SCUBA-2: a 10,000 pixel submillimeter camera for the James Clerk Maxwell Telescope
• Large Area Mapping at 850 Microns. V. Analysis of the Clump Distribution in the Orion A South Molecular Cloud
• Observational Constraints on Submillimeter Dust Opacity
• A census of molecular hydrogen outflows and their sources along the Orion A molecular ridge: characteristics and overall distribution
• The JCMT Legacy Survey of the Gould Belt: a first look at Serpens with HARP
• A far-infrared molecular and atomic line survey of the Orion KL region
• "Starless" Super-Jeans Cores in Four Gould Belt Clouds

Cited by in corpus (40)

• An ALMA study of the Orion Integral Filament: I. Evidence for narrow fibers in a massive cloud
• The JCMT BISTRO Survey: The magnetic field strength in the Orion A filament
• Disruption of the Orion Molecular Core 1 by the stellar wind of the massive star ${\theta }^1$ Ori C
• Revealing the physical properties of molecular gas in Orion with a large scale survey in J=2-1 lines of 12CO, 13CO and C18O
• CO Abundance Variations in the Orion Molecular Cloud
• Orion Revisited - I. The massive cluster in front of the Orion Nebula Cluster
• The CARMA-NRO Orion Survey
• High abundance ratio of ${}^{13}$CO to C${}^{18}$O toward photon-dominated regions in the Orion-A giant molecular cloud
• Opacity broadening and interpretation of suprathermal CO linewidths: Macroscopic Turbulence and Tangled Molecular Clouds
• Hierarchical Fragmentation of the Orion Molecular Filaments
• Calibration of the Herschel SPIRE Fourier Transform Spectrometer
• Tearing the Veil: interaction of the Orion Nebula with its neutral environment
• Helical Magnetic Fields in Molecular Clouds? A New Method to Determine the Line-of-Sight Magnetic Field Structure in Molecular Clouds
• The JCMT Gould Belt Survey: A First Look at Southern Orion A with SCUBA-2
• The Orion HII Region and the Orion Bar in the Mid-Infrared
• The JCMT Legacy Survey of the Gould Belt: a molecular line study of the Ophiuchus molecular cloud
• An X-rays Survey of the Young Stellar Population of the Lynds 1641 and Iota Orionis Regions
• The JCMT BISTRO Survey: The Distribution of Magnetic Field Strengths towards the OMC-1 Region
• IRAM-30m large scale survey of ${}^{12}$CO(2-1) and ${}^{13}$CO(2-1) emission in the Orion molecular cloud
• The JCMT Gould Belt Survey: Dense Core Clusters in Orion A
• Catalog of dense cores in the Orion A giant molecular cloud
• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. III. The Orion Molecular Cloud 1
• Nobeyama 45-m mapping observations toward nearby molecular clouds, Orion A, Aquila Rift, and M17: Project overview
• Planck Cold Clumps in the $\lambda$ Orionis complex. II. Environmental effects on core formation
• Orion A's complete 3D magnetic field morphology
• Molecular globules in the Veil bubble of Orion. IRAM 30m 12CO, 13CO, and C18O 2-1 expanded maps of Orion A
• The CARMA-NRO Orion Survey: Protostellar Outflows, Energetics, and Filamentary Alignment
• Bright Extragalactic ALMA Redshift Survey (BEARS) III: Detailed study of emission lines from 71 Herschel targets
• The JCMT Gould Belt Survey: the effect of molecular contamination in SCUBA-2 observations of Orion A
• Earliest Stages of Protocluster Formation: Substructure and Kinematics of Starless Cores in Orion
• Nobeyama 45 m Mapping Observations toward Orion A. II. Classification of cloud structures and variation of the ${}^{13}$CO/C${}^{18}$O abundance ratio due to far-UV Radiation
• Expanding CO Shells in the Orion A Molecular Cloud
• Assessing molecular line diagnostics of triggered star formation using synthetic observations
• ALMA Fragmented Source Catalogue in Orion (FraSCO) I. Outflow interaction within an embedded cluster in OMC-2/FIR3, FIR4, and FIR5
• ALMA Observations of Giant Molecular Clouds in M33. II. Triggered High-mass Star Formation by Multiple Gas Colliding Events at the NGC 604 Complex
• Evolution of the Hub-filament Structures in IC 5146 in the Context of the Energy Balance of Gravity, Turbulence, and Magnetic Field
• The APEX Large CO Heterodyne Orion Legacy Survey (ALCOHOLS). I. Survey overview
• Bow Magnetic Morphology Surrounding Filamentary Molecular Clouds? 3D Magnetic Field Structure of Orion-A
• Detection of a turbulent gas component associated with a starless core with subthermal turbulence in the Orion A cloud
• Herschel SPIRE FTS Spectral Mapping Calibration