ALMA Observations of Atomic Carbon [C I] (${{}^3\mathrm{P}}_1\to {{}^3\mathrm{P}}_0$) and Low-$J$ CO Lines in the Starburst Galaxy NGC 1808

Abstract

We present [C I] (${{}^3\mathrm{P}}_1\to {{}^3\mathrm{P}}_0$), ${}^{12}$CO, ${}^{13}$CO, and C${}^{18}$O ($J=2\to 1$) observations of the central region (radius 1 kpc) of the starburst galaxy NGC 1808 at 30-50 pc resolution conducted with Atacama Large Millimeter/submillimeter Array. Radiative transfer analysis of multiline data indicates warm ($T_{\mathrm{k}}\sim 40-80$ K) and dense ($n_{{\mathrm{H}}_2}\sim 10^{3-4}$ cm${}^{-3}$) molecular gas with high column density of atomic carbon ($N_{\mathrm{CI}}\sim 3\times 10^{18}$ cm${}^{-2}$) in the circumnuclear disk (central 100 pc). The C I/H${}_2$ abundance in the central 1 kpc is $\sim 3-7\times 10^{-5}$, consistent with the values in luminous infrared galaxies. The intensity ratios of [C I]/CO(1-0) and [C I]/CO(3-2), respectively, decrease and increase with radius in the central 1 kpc, whereas [C I]/CO(2-1) is uniform within statistical errors. The result can be explained by excitation and optical depth effects, since the effective critical density of CO (2-1) is comparable to that of [C I]. The distribution of [C I] is similar to that of ${}^{13}$CO (2-1), and the ratios of [C I] to ${}^{13}$CO (2-1) and C${}^{18}$O (2-1) are uniform within $\sim 30\%$ in the central $<400$ pc starburst disk. The results suggest that [C I] (${{}^3\mathrm{P}}_1\to {{}^3\mathrm{P}}_0$) luminosity can be used as a CO-equivalent tracer of molecular gas mass, although caution is needed when applied in resolved starburst nuclei (e.g., circumnuclear disk), where the [C I]/CO(1-0) luminosity ratio is enhanced due to high excitation and atomic carbon abundance. The [C I]/CO(1-0) intensity ratio toward the base of the starburst-driven outflow is $\lesssim 0.15$, and the upper limits of the mass and kinetic energy of the atomic carbon outflow are $\sim 1\times 10^4{M}_{\odot }$ and $\sim 3\times 10^{51}$ erg, respectively.

arXiv commentAccepted for publication in ApJ (30 pages, 15 figures)

References in corpus (61)

• The CO-to-H2 Conversion Factor
• A computer program for fast non-LTE analysis of interstellar line spectra
• Molecular Gas and Star Formation in Nearby Disk Galaxies
• Physical Conditions in Regions of Star Formation
• The CO-to-H2 Conversion Factor and Dust-to-Gas Ratio on Kiloparsec Scales in Nearby Galaxies
• On the effect of the Cosmic Microwave Background in high-redshift (sub-)millimeter observations
• 3D Integral Field Observations of Ten Galactic Winds - I. Extended phase (>10 Myr) of mass/energy injection before the wind blows
• The CI lines as tracers of molecular gas, and their prospects at high redshifts
• Gas and Dust in the Cloverleaf Quasar at Redshift 2.5
• ALMA observations of molecular tori around massive black holes
• A Survey of Atomic Carbon at High Redshift
• Molecular line emission in NGC1068 imaged with ALMA: II. The chemistry of the dense molecular gas
• The Properties of the Interstellar Medium within a Star-Forming Galaxy at z=2.3
• ALMA observations of atomic carbon in z~4 dusty star-forming galaxies
• SMA/PdBI multiple line observations of the nearby Seyfert2 galaxy NGC 1068: Shock related gas kinematics and heating in the central 100pc?
• Cosmic-ray induced destruction of CO in star-forming galaxies
• Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z~2-4 as probed by multi-J CO lines
• A Survey of Atomic Carbon [C I] in High-redshift Main-Sequence Galaxies
• Multiple CO Transitions, CI, and HCN from the Cloverleaf Quasar
• The AST/RO Survey of the Galactic Center Region. I. The Inner 3 Degrees
• CI emission in Ultra Luminous Infrared Galaxies as a molecular gas mass tracer
• Atomic carbon at redshift ~2.5
• Circumnuclear Multi-phase Gas in the Circinus Galaxy II: The Molecular and Atomic Obscuring Structures Revealed with ALMA
• Using [CI] to probe the Interstellar Medium in z~2.5 Sub-Millimeter Galaxies
• Atomic Carbon in Galaxies
• Molecular gas chemistry in AGN. II. High-resolution imaging of SiO emission in NGC1068: shocks or XDR?
• Modelling [CI] emission from turbulent molecular clouds
• HNCO enhancement by shocks in the L1157 molecular outflow
• Herschel-SPIRE Imaging Spectroscopy of Molecular Gas in M82
• Atomic Carbon in M82: Physical conditions derived from simultaneous observations of the [CI] fine structure submillimeter wave transitions
• ALMA reveals starburst-like interstellar medium conditions in a compact star-forming galaxy at z ~ 2 using [CI] and CO
• Neutral Atomic Carbon in Centers of Galaxies
• An Alternative Accurate Tracer of Molecular Clouds: The "$X_{\mathrm{CI}}$-Factor"
• ALMA [CI]${}^3{P}_1{-}^3{P}_0$ observations of NGC6240: a puzzling molecular outflow, and the role of outflows in the global ${\alpha }_{\mathrm{CO}}$ factor of (U)LIRGs
• The Density and Temperature of Molecular Clouds in M33
• Giant galaxy growing from recycled gas: ALMA maps the circumgalactic molecular medium of the Spiderweb in [CI]
• Neutral carbon and CO in 76 (U)LIRGs and starburst galaxy centers A method to determine molecular gas properties in luminous galaxies
• Neutral Carbon Emission in luminous infrared galaxies The \CI\ Lines as Total Molecular Gas Tracers
• AST/RO Observations of Atomic Carbon near the Galactic Center
• Gas Dynamics and Outflow in the Barred Starburst Galaxy NGC 1808 Revealed with ALMA
• New places and phases of CO-poor/CI-rich molecular gas in the Universe
• PAH emission variations within the resolved starbursts of NGC253 and NGC1808
• Distributions of molecules in the circumnuclear disk and surrounding starburst ring in the Seyfert galaxy NGC 1068 observed with ALMA
• Large-scale mapping observations of the CI(3P1-3P0) and CO(J=3-2) lines toward the Orion A molecular cloud
• Resolved neutral carbon emission in nearby galaxies: [CI] Lines as Total Molecular Gas Tracers
• Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions
• Planck's Dusty GEMS. VII. Atomic carbon and molecular gas in dusty starburst galaxies at z=2 to 4
• Atomic Carbon and CO Isotope Emission in the Vicinity of DR15
• Extensive [CI] Mapping toward the Orion-A Molecular Cloud
• Molecular shock tracers in NGC 1068: SiO and HNCO
• Velocity profiles of [CII], [CI], CO, and [OI] and physical conditions in four star-forming regions in the Large Magellanic Cloud
• Atomic carbon as a powerful tracer of molecular gas in the high-redshift Universe: perspectives for ALMA
• Atomic Carbon Is a Temperature Probe in Dark Clouds
• High Atomic Carbon Abundance in Molecular Clouds in the Galactic Center Region
• Star formation and gas flows in the centre of the NUGA galaxy NGC 1808 observed with SINFONI
• Dense molecular gas in the starburst nucleus of NGC 1808
• ALMA [CI] observations toward the central region of a Seyfert galaxy NGC 613
• Evolution of Molecular Clouds in the Superwind Galaxy NGC 1808 Probed by ALMA Observations
• The Astrochemical Impact of Cosmic Rays in Protoclusters II: CI-to-H${}_2$ and CO-to-H${}_2$ Conversion Factors
• Embedded clusters in NGC1808 central starburst - Near-infrared imaging and spectroscopy
• Photon Dominated Regions in NGC 3603

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• Extremely Low Molecular Gas Content in the Vicinity of a Red Nugget Galaxy at $z=1.91$
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