The G332 molecular cloud ring: I. Morphology and physical characteristics

Abstract

We present a morphological and physical analysis of a Giant Molecular Cloud (GMC) using the carbon monoxide isotopologues (${}^{12}$CO, ${}^{13}$CO, C${}^{18}$O ${}^3{P}_2\to$ ${}^3{P}_1$) survey of the Galactic Plane (Mopra CO Southern Galactic Plane Survey), supplemented with neutral carbon maps from the HEAT telescope in Antarctica. The giant molecular cloud structure (hereinafter the ring) covers the sky region $332^{\circ }$ < $\ell$ < $333^{\circ }$ and $b$ = $\pm 0.5^{\circ }$ (hereinafter the G332 region). The mass of the ring and its distance are determined to be respectively ~2$\times 10^5{\mathrm{M}}_{\odot }$ and ~3.7 kpc from Sun. The dark molecular gas fraction, estimated from the ${}^{13}$CO and [CI] lines, is $\sim 17\%$ for a CO T${}_{\mathrm{ex}}$ between [10,20 K]. Comparing the [CI] integrated intensity and N(H${}_2$) traced by ${}^{13}$CO and ${}^{12}$CO, we define an X${}_{\mathrm{CI}}^{809}$ factor, analogous to the usual X${}_{\mathrm{co}}$, through the [CI] line. X${}_{\mathrm{CI}}^{809}$ ranges between [1.8,2.0]$\times 10^{21}{\mathrm{cm}}^{-2}{\mathrm{K}}^{-1}{\mathrm{km}}^{-1}\mathrm{s}$. We examined local variation in X${}_{\mathrm{co}}$ and T${}_{\mathrm{ex}}$ across the cloud, and find in regions where the star formation activity is not in an advanced state, an increase in the mean and dispersion of the X${}_{\mathrm{co}}$ factor as the excitation temperature decreases. We present a catalogue of C${}^{18}$O clumps within the cloud. The star formation (SF) activity ongoing in the cloud shows a correlation with T${}_{\mathrm{ex}}$, [CI] and CO emissions, and anti-correlation with X${}_{\mathrm{co}}$, suggesting a North-South spatial gradient in the SF activity. We propose a method to disentangle dust emission across the Galaxy, using HI and ${}^{13}$CO data. We describe Virtual Reality (VR) and Augmented Reality (AR) data visualisation techniques for the analysis of radio astronomy data.

arXiv comment30 pages, 34 figures, Accepted for publication on MNRAS. 3D Virtual Reality view of the cloud here: http://hologhost.altervista.org/VR/index.html#

References in corpus (66)

• Astropy: A Community Python Package for Astronomy
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The SIMBAD astronomical database
• The CO-to-H2 Conversion Factor
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• The Cologne Database for Molecular Spectroscopy, CDMS, in the Virtual Atomic and Molecular Data Centre, VAMDC
• The Dark Molecular Gas
• ATLASGAL - The APEX Telescope Large Area Survey of the Galaxy at 870 microns
• The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• The AKARI/IRC Mid-Infrared All-Sky Survey
• Hi-GAL: the Herschel infrared Galactic Plane Survey
• Infrared Dark Clouds: precursors to star clusters
• The VLA Galactic Plane Survey
• How to Calculate Molecular Column Density
• The Southern Galactic Plane Survey: HI Observations and Analysis
• Cluster-formation in the Rosette molecular cloud at the junctions of filaments
• Bias-free Measurement of Giant Molecular Cloud Properties
• The initial conditions of stellar protocluster formation. I. A catalogue of Spitzer dark clouds
• Planck 2013 results. XII. Component separation
• The Bolocam Galactic Plane Survey: Survey Description and Data Reduction
• A Parallax-based Distance Estimator for Spiral Arm Sources
• ATLASGAL - Compact source catalogue: 330 < l < 21 degrees
• The 6-GHz methanol multibeam maser catalogue I: Galactic Centre region, longitudes 345 to 6
• ATLASGAL --- towards a complete sample of massive star forming clumps
• Intrinsically Red Sources observed by Spitzer in the Galactic Mid-Plane
• The Milky Way Project First Data Release: A Bubblier Galactic Disk
• A Catalog of MSX Infrared Dark Cloud Candidates
• FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) I: Project Overview and Initial Results
• Properties of Hi-GAL clumps in the inner Galaxy]{The Hi-GAL compact source catalogue. I. The physical properties of the clumps in the inner Galaxy ($-71.0^{\circ }<\ell <67.0^{\circ }$)
• Modeling CO Emission: I. CO as a Column Density Tracer and the X-Factor in Molecular Clouds
• Spectral imaging of the Central Molecular Zone in multiple 3-mm molecular lines
• MALT90: The Millimetre Astronomy Legacy Team 90 GHz Survey
• The 6-GHz Multibeam Maser Survey I. Techniques
• A 24 Micron Point Source Catalog of the Galactic Plane from Spitzer/MIPSGAL
• SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium
• Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth Quadrant
• The first Hi-GAL observations of the outer Galaxy: a look to star formation in the third Galactic quadrant in the longitude range 216.5 < l < 225.5
• Southern class I methanol masers at 36 and 44 GHz
• The Mopra Southern Galactic Plane CO Survey
• The Three-mm Ultimate Mopra Milky Way Survey. I. Survey Overview, Initial Data Releases, and First Results
• Modelling [CI] emission from turbulent molecular clouds
• Correlation Between Gas and Dust in Molecular Clouds: L977
• The H2O southern Galactic Plane Survey(HOPS): NH3 (1,1) and (2,2) catalogues
• Synthetic C${}^{18}$O observations of fibrous filaments: the problems of mapping from PPV to PPP
• Accurate water maser positions from HOPS
• An Alternative Accurate Tracer of Molecular Clouds: The "$X_{\mathrm{CI}}$-Factor"
• Radio-millimetre investigation of galactic infrared dark clouds
• Catalog of observed tangents to the spiral arms in the Milky Way galaxy
• Spectral imaging of the Central Molecular Zone in multiple 7-mm molecular lines
• The Initial Conditions of Stellar Protocluster Formation: III. The Herschel counterparts of the Spitzer Dark Cloud catalogue
• The Relationship Between the Dust and Gas-Phase CO Across the California Molecular Cloud
• The Carina Nebula and Gum 31 molecular complex: I. Molecular gas distribution, column densities and dust temperatures
• The Mopra Southern Galactic Plane CO Survey - Data Release 3
• A New 95 GHz Methanol Maser Catalog: I. Data
• Atomic Carbon and CO Isotope Emission in the Vicinity of DR15
• Submillimeter mapping and analysis of cold dust condensations in the Orion M42 star forming complex
• Remarkable analytic relations among greybody parameters
• The Mopra Southern Galactic Plane CO Survey - Data Release 1
• Extended Carbon Line Emission in the Galaxy: Searching for Dark Molecular Gas along the G328 Sightline
• Augmented Reality in Astrophysics
• An analysis of star formation with Herschel in the Hi-GAL Survey. II. The tips of the Galactic bar
• Immersive Virtual Reality Experiences for All-Sky Data
• 3D visualization of astronomy data cubes using immersive displays
• The Carbon Inventory in a Quiescent, Filamentary Molecular Cloud in G328
• HI Emission and Absorption in the Southern Galactic Plane Survey

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