The Green Bank Ammonia Survey (GAS): First Results of NH3 mapping the Gould Belt

Abstract

We present an overview of the first data release (DR1) and first-look science from the Green Bank Ammonia Survey (GAS). GAS is a Large Program at the Green Bank Telescope to map all Gould Belt star-forming regions with $A_V\gtrsim 7$ mag visible from the northern hemisphere in emission from NH${}_3$ and other key molecular tracers. This first release includes the data for four regions in Gould Belt clouds: B18 in Taurus, NGC 1333 in Perseus, L1688 in Ophiuchus, and Orion A North in Orion. We compare the NH${}_3$ emission to dust continuum emission from Herschel, and find that the two tracers correspond closely. NH${}_3$ is present in over 60\% of lines-of-sight with $A_V\gtrsim 7$ mag in three of the four DR1 regions, in agreement with expectations from previous observations. The sole exception is B18, where NH${}_3$ is detected toward ~ 40\% of lines-of-sight with $A_V\gtrsim 7$ mag. Moreover, we find that the NH${}_3$ emission is generally extended beyond the typical 0.1 pc length scales of dense cores. We produce maps of the gas kinematics, temperature, and NH${}_3$ column densities through forward modeling of the hyperfine structure of the NH${}_3$ (1,1) and (2,2) lines. We show that the NH${}_3$ velocity dispersion, ${\sigma }_v$, and gas kinetic temperature, $T_K$, vary systematically between the regions included in this release, with an increase in both the mean value and spread of ${\sigma }_v$ and $T_K$ with increasing star formation activity. The data presented in this paper are publicly available.

33 pages, 27 figures, accepted to ApJS. Datasets are publicly available: https://dataverse.harvard.edu/dataverse/GAS_DR1

References in corpus (24)

• The distance to the Orion Nebula
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• Spitzer Observations of NGC 1333: A Study of Structure and Evolution in a Nearby Embedded Cluster
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• The COMPLETE Survey of Star-Forming Regions: Phase I Data
• Molecular gas kinematics within the central 250 pc of the Milky Way
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• An Ammonia Spectral Atlas of Dense Cores in Perseus
• Comparing Star Formation on Large Scales in the c2d Legacy Clouds: Bolocam 1.1 mm Dust Continuum Surveys of Serpens, Perseus, and Ophiuchus
• A Large Catalog of Accurate Distances to Molecular Clouds from PS1 Photometry
• The Gould's Belt Distances Survey (GOBELINS) I. Trigonometric parallax distances and depth of the Ophiuchus complex
• The Spitzer Space Telescope Survey of the Orion A and B Molecular Clouds II: the Spatial Distribution and Demographics of Dusty Young Stellar Objects
• The James Clerk Maxwell Telescope Legacy Survey of Nearby Star-forming Regions in the Gould Belt
• The On The Fly Imaging Technique
• Current Star Formation in the Ophiuchus and Perseus Molecular Clouds: Constraints and Comparisons from Unbiased Submillimeter and Mid-Infrared Surveys. II
• The Musca cloud: A 6 pc-long velocity-coherent, sonic filament
• A closer look at the "characteristic" width of molecular cloud filaments
• Investigating the structure and fragmentation of a highly filamentary IRDC
• An Ammonia Spectral Map of the L1495-B218 Filaments in the Taurus Molecular Cloud : I. Physical Properties of Filaments and Dense cores
• CARMA Large Area Star Formation Survey: Project Overview with Analysis of Dense Gas Structure and Kinematics in Barnard 1
• The fragmentation and stability of hierarchical structure in Serpens South
• How chemistry influences cloud structure, star formation, and the IMF
• HfS, Hyperfine Structure Fitting Tool
• The Interplay of Turbulence & Magnetic Fields in Star-Forming Regions: Simulations and Observations

Cited by in corpus (119)

• An ALMA study of the Orion Integral Filament: I. Evidence for narrow fibers in a massive cloud
• Seeds Of Life In Space (SOLIS): The organic composition diversity at 300--1000 au scale in Solar-type star forming regions
• Gas phase Elemental abundances in Molecular cloudS (GEMS) I. The prototypical dark cloud TMC 1
• The Perseus ALMA Chemistry Survey (PEACHES). I. The Complex Organic Molecules in Perseus Embedded Protostars
• HCN/HNC intensity ratio: a new chemical thermometer for the molecular ISM
• PRODIGE -- Envelope to disk with NOEMA I. A 3000 au streamer feeding a Class I protostar
• Distances and Kinematics of Gould Belt Star-Forming Regions with Gaia DR2 results
• pyspeckit: A spectroscopic analysis and plotting package
• SOLIS II. Carbon-chain growth in the Solar-type protocluster OMC2-FIR4
• The Green Bank Ammonia Survey: Dense Cores Under Pressure in Orion A
• Gas phase Elemental abundances in Molecular cloudS (GEMS). II. On the quest for the sulphur reservoir in molecular clouds: the $H_{2}S$ case
• High-Resolution ALMA Observations of HD100546: Asymmetric Circumstellar Ring, and Circumplanetary Disk Upper Limits
• Gas phase Elemental abundances in Molecular cloudS (GEMS) VII. Sulfur elemental abundance
• ALMA observations of fragmentation, sub-structure, and protostars in high-mass starless clump candidates
• Droplets I: Pressure-Dominated Sub-0.1 pc Coherent Structures in L1688 and B18
• Zooming in on Individual Star Formation: Low- and High-mass Stars
• The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-Forming Region
• Velocity-coherent Filaments in NGC 1333: Evidence for Accretion Flow?
• Dense gas kinematics and a narrow filament in the Orion A OMC1 region using NH3
• Gas phase Elemental abundances in Molecular cloudS (GEMS). IV. Observational results and statistical trends
• From the CMF to the IMF: Beyond the Core-Collapse Model
• The Origin of the Stellar Mass Distribution and Multiplicity
• Disk masses in the Orion Molecular Cloud-2: distinguishing time and environment
• The Astrochemical Impact of Cosmic Rays in Protoclusters I: Molecular Cloud Chemistry
• The far-infrared polarization spectrum of Rho Ophiuchi A from HAWC+/SOFIA observations
• FRagmentation and Evolution of dense cores Judged by ALMA (FREJA). I (Overview). Inner $\sim$1000 au structures of prestellar/protostellar cores in Taurus
• A statistical analysis of dust polarization properties in ALMA observations of Class 0 protostellar cores
• The specific angular momentum radial profile in dense cores: improved initial conditions for disk formation
• Turbulence, Coherence and Collapse: Three Phases for Core Evolution
• ALMA observations of NGC 6334S $-$ I: Forming massive stars and cluster in subsonic and transonic filamentary clouds
• Modeling deuterium chemistry in starless cores: full scrambling versus proton hop
• A dynamically young, gravitationally stable network of filaments in Orion B
• Temperature structure and kinematics of the IRDC G035.39-00.33
• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. III. The Orion Molecular Cloud 1
• KFPA Examinations of Young STellar Object Natal Environments (KEYSTONE): Hierarchical Ammonia Structures in Galactic Giant Molecular Clouds
• An Interferometric View of H-MM1. I. Direct Observation of NH3 Depletion
• The Green Bank Ammonia Survey: A Virial Analysis of Gould Belt Clouds in Data Release 1
• ALMA detections of the youngest protostars in Ophiuchus
• A Solar System formation analogue in the Ophiuchus star-forming complex
• Probing the physics of star formation (ProPStar): I. First resolved maps of the electron fraction and cosmic-ray ionization rate in NGC 1333
• Gas velocity structure of the Orion A Integral Shaped Filament
• Efficient methanol production on the dark side of a prestellar core
• Maps of Magnetic Field Strength in the OMC-1 using HAWC+ FIR Polarimetric data
• Magnetic Field Structure in Spheroidal Star-Forming Clouds
• Connecting the Scales: Large Area High-resolution Ammonia Mapping of NGC 1333
• A 2-3 mm high-resolution molecular line survey towards the centre of the nearby spiral galaxy NGC 6946
• The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251
• Neutral vs Ion Linewidths in Barnard 5: Evidence for Penetration by MHD Waves
• Methanol Mapping in Cold Cores: Testing Model Predictions
• Characterizing the line emission from molecular clouds. II. A comparative study of California, Perseus, and Orion A
• Transition from Coherent Cores to Surrounding Cloud in L1688
• Probing the Physics of Star-Formation (ProPStar): II. The first systematic search for streamers toward protostars
• Subsonic islands within a high-mass star-forming IRDC
• Probabilistic detection of spectral line components
• The Discovery of a New Massive Molecular Gas Component Associated with the Submillimeter Galaxy SMM J02399-0136
• Dissecting the super-critical filaments embedded in the 0.5 pc subsonic region of Barnard 5
• Low Mass Stars as Tracers of Star and Cluster Formation
• Multicomponent kinematics in a massive filamentary IRDC
• Droplets II: Internal Velocity Structures and Potential Rotational Motions in Pressure-dominated Coherent Structures
• Extended ammonia observations towards the 'Integral-Shaped Filament'
• Relative Alignment between Dense Molecular Cores and Ambient Magnetic Field: The Synergy of Numerical Models and Observations
• Molecular line signatures of cloud-cloud collisions
• Ubiquitous $\mathrm{N}{\mathrm{H}}_3$ supersonic component in L1688 coherent cores
• Multi-scale analysis of the Monoceros OB 1 star-forming region: I. The dense core population
• An International Survey of Front-End Receivers and Observing Performance of Telescopes for Radio Astronomy
• Evidence of a Cloud-Cloud Collision from Overshooting Gas in the Galactic Center
• Magnetic Field Structure of Dense Cores using Spectroscopic Methods
• Nitrogen fractionation in ammonia and its insights on nitrogen chemistry
• The impact of episodic outflow feedback on stellar multiplicity and the star formation efficiency
• Resolution-dependent Subsonic Non-thermal Line Dispersion Revealed by ALMA
• Parsec-scale cosmic-ray ionisation rate in Orion
• Alignment of dense molecular core morphology and velocity gradients with ambient magnetic fields
• A turbulent origin for the complex envelope kinematics in the young low-mass core Per-Bolo 58
• Evidence for dense gas heated by the explosion in Orion KL
• The Green Bank Ammonia Survey: Unveiling the Dynamics of the Barnard 59 star-forming Clump
• VLA ammonia observations of L1287: analysis of the "Guitar" core and two filaments
• TIMES I: a Systematic Observation in Multiple Molecular Lines Toward the Orion A and Ophiuchus Clouds
• 3D Radiative Transfer Modelling and Virial Analysis of Starless Cores in the B10 Region of the Taurus Molecular Cloud
• Variation of the Core Lifetime and Fragmentation Scale in Molecular Clouds as an Indication of Ambipolar Diffusion
• APEX-SEPIA660 Early Science: Gas at densities above $10^7$ cm${}^{-3}$ towards OMC-1
• The CARMA-NRO Orion Survey: Filament Formation via Collision-Induced Magnetic Reconnection -- The Stick in Orion A
• Ammonia observations towards the Aquila Rift cloud complex
• Magnetic Field of Molecular Gas Measured with the Velocity Gradient Technique I. Orion A
• NH${}_3$ (1,1) hyperfine intensity anomalies in the Orion A molecular cloud
• The distribution of ionized, atomic and PDR gas around S1 in Rho Ophiuchus
• No nitrogen fractionation on 600 au scale in the Sun progenitor analogue OMC-2 FIR4
• An imaging line survey of OMC-1 to OMC-3
• No impact of core-scale magnetic field, turbulence, or velocity gradient on sizes of protostellar disks in Orion A
• The ionization fraction in OMC-2 and OMC-3
• Hyperfine Group Ratio: A Recipe for Deriving Kinetic Temperature from Ammonia Inversion Lines
• VLA and NOEMA view of the Bok Globule CB 17: the starless nature of a proposed FHSC candidate
• A Survey of Deuterated Ammonia in the Cepheus Star-Forming Region L1251
• An ALMA search for substructure and fragmentation in starless cores in Orion B North
• Velocity-Coherent Substructure in TMC-1: Inflow and Fragmentation
• The CARMA-NRO Orion Survey: Core Emergence and Kinematics in the Orion A Cloud
• NH${}_3$ Observations of the S235 Star Forming Region: Dense Gas in Inter-core Bridges
• A Tale of Three: Magnetic Fields along the Orion Integral-Shaped Filament as Revealed by JCMT BISTRO survey
• The JCMT Gould Belt Survey: radiative heating by OB stars
• Robustness of Synthetic Observations in Producing Observed Core Properties: Predictions for the TolTEC Clouds to Cores Legacy Survey
• Probing the Physics of Star-Formation (ProPStar) III. No evidence for dissipation of turbulence down to 20 mpc (4 000 au) scale
• Understanding biases in measurements of molecular cloud kinematics using line emission
• A study of 90 GHz dust emissivity on molecular cloud and filament scales
• Searching for further evidence for cloud-cloud collisions in L1188
• CLOVER: Convnet Line-fitting Of Velocities in Emission-line Regions
• Using Molecular Gas Observations to Guide Initial Conditions for Star Cluster Simulations
• Deuterium fractionation in cold dense cores in the low-mass star forming region L1688
• Asymmetric accretion through a streamer onto the pre-stellar core H-MM1
• The JCMT Gould Belt Survey Complete Core Catalogue: Core mass function variations between nearby molecular clouds
• The factors that influence protostellar multiplicity I: Gas temperature, density, and mass in Perseus with Nobeyama
• Updated Inventory of Carbon Monoxide in The Taurus Molecular Cloud
• Gas phase Elemental abundances in Molecular cloudS (GEMS). X. Observational effects of turbulence on the chemistry of molecular clouds
• Does the HCN/CO ratio trace the star-forming fraction of gas? II. Variations in CO and HCN Emissivity
• Chemical templates of the Central Molecular Zone. Shock and protostellar object signatures under Galactic Center conditions
• Fine-tuning the complex organic molecule formation: sulfur and CO ice as regulators of surface chemistry
• Magnetic field alignment with dense cores in the transition between cloud and core scales
• The factors that influence protostellar multiplicity II. Gas temperature and mass in Perseus with APEX
• KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Star formation feedback on dense molecular gas in the W33 complex
• Chemical analysis of prestellar cores in Ophiuchus yields short timescales and rapid collapse
• Chemistry of Dark Molecular Clouds