KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Discovery of parsec-scale CO depletion in the Canis Major star-forming region

Abstract

In observational studies of infrared dark clouds, the number of detections of CO freeze-out onto dust grains (CO depletion) at pc-scale is extremely limited, and the conditions for its occurrence are, therefore, still unknown. We report a new object where pc-scale CO depletion is expected. As a part of Kagoshima Galactic Object survey with Nobeyama 45-m telescope by Mapping in Ammonia lines (KAGONMA), we have made mapping observations of NH3 inversion transition lines towards the star-forming region associated with the CMa OB1 including IRAS 07077-1026, IRAS 07081-1028, and PGCC G224.28-0.82. By comparing the spatial distributions of the NH3 (1,1) and C18O (J=1-0), an intensity anti-correlation was found in IRAS 07077-1026 and IRAS 07081-1028 on the ~1 pc scale. Furthermore, we obtained a lower abundance of C18O at least in IRAS 07077-1026 than in the other parts of the star-forming region. After examining high density gas dissipation, photodissociation, and CO depletion, we concluded that the intensity anti-correlation in IRAS 07077-1026 is due to CO depletion. On the other hand, in the vicinity of the centre of PGCC G224.28-0.82, the emission line intensities of both the NH3 (1,1) and C18O (J=1-0) were strongly detected, although the gas temperature and density were similar to IRAS 07077-1026. This indicates that there are situations where C18O (J=1-0) cannot trace dense gas on the pc scale and implies that the conditional differences that C18O (J=1-0) can and cannot trace dense gas are unclear.

arXiv comment20 pages, 16 figures, 4 tables, accepted for Publications of the Astronomical Society of Japan (PASJ)

References in corpus (63)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• The Herschel-SPIRE instrument and its in-flight performance
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Cold Dark Clouds: The Initial Conditions for Star Formation
• Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Structural Analysis of Molecular Clouds: Dendrograms
• Systematic Molecular Differentiation in Starless Cores
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• How to Calculate Molecular Column Density
• The WISE Catalog of Galactic HII Regions
• Observing the gas temperature drop in the high-density nucleus of L 1544
• CO Isotopologues in the Perseus Molecular Cloud Complex: the X-Factor and Regional Variations
• Molecular Inventories and Chemical Evolution of Low-mass Protostellar Envelopes
• How Many Infrared Dark Clouds can form Massive Stars and Clusters?
• Planck Early Results: Thermal dust in Nearby Molecular Clouds
• Herschel-Planck dust optical-depth and column-density maps: I. Method description and results for Orion
• The anatomy of the Orion B Giant Molecular Cloud: A local template for studies of nearby galaxies
• FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) I: Project Overview and Initial Results
• First detection of water vapor in a pre-stellar core
• The RMS Survey: Ammonia and water maser analysis of massive star forming regions
• The identification of filaments on far infrared and submillimiter images. Morphology, physical conditions and relation with star formation of filamentary structure
• 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
• CO Abundance Variations in the Orion Molecular Cloud
• Mapping Large-Scale CO Depletion in a Filamentary Infrared Dark Cloud
• Double DCO+ rings reveal CO ice desorption in the outer disk around IM Lup
• ATLASGAL-selected massive clumps in the inner Galaxy: V. Temperature structure and evolution
• Probing the initial conditions of High Mass Star formation -- I. Deuteration and depletion in high mass pre/protocluster clumps
• High abundance ratio of ${}^{13}$CO to C${}^{18}$O toward photon-dominated regions in the Orion-A giant molecular cloud
• Calibration of evolutionary diagnostics in high-mass star formation
• High CO depletion in southern infrared-dark clouds
• Gas Kinematics and Excitation in the Filamentary IRDC G035.39-00.33
• Resolved Depletion Zones and Spatial Differentiation of N2H+ and N2D+
• Why does ammonia not freeze out in the center of pre-stellar cores?
• Lighting the dark molecular gas: H${}_2$ as a direct tracer
• A WISE Census of Young Stellar Objects in Canis Major
• A Pre-Protostellar Core in L1551
• Astrochemical Properties of Planck Cold Clumps
• Outflow detection in a 70 $\mu$m dark high-mass core
• Are Infrared Dark Clouds Really Quiescent?
• Temperature structure and kinematics of the IRDC G035.39-00.33
• A search for water masers associated with class II methanol masers - II. Longitude range 341${}^{\circ }$ to 6${}^{\circ }$
• On the size of the CO-depletion radius in the IRDC G351.77-0.51
• The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VI. The core-scale CO-depletion
• The chemical structure of young high-mass star-forming clumps: (II) parsec-scale CO depletion and deuterium fraction of $\mathrm{HC}{\mathrm{O}}^{+}$
• Connecting the Scales: Large Area High-resolution Ammonia Mapping of NGC 1333
• The Serpens filament: at the onset of slightly supercritical collapse
• The Core Mass Function in the Orion Nebula Cluster Region: What Determines the Final Stellar Masses?
• Identifying Young Stellar Objects in the Outer Galaxy: l = 224 deg Region in Canis Major
• A network of filaments detected by Herschel in the Serpens Core: A laboratory to test simulations of low-mass star formation
• Probing the Cold Deep Depths of the California Molecular Cloud: The Icy Relationship between CO and Dust
• The segregation of starless and protostellar clumps in the Hi-GAL l=224deg region
• Three isotopologues CO survey of Molecular Clouds in the CMa OB1 complex
• NH${}_3$ (1,1) hyperfine intensity anomalies in the Orion A molecular cloud
• Three dimensional projection effects on chemistry in a Planck galactic cold clump
• Hyperfine Group Ratio: A Recipe for Deriving Kinetic Temperature from Ammonia Inversion Lines
• Ammonia mapping observations toward the Galactic massive star-forming region Sh 2-255 and Sh 2-257
• Ammonia mapping observations of the Galactic infrared bubble N49: Three NH${}_3$ clumps along the molecular filament

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