[CI](1-0) and [CI](2-1) in resolved local galaxies

Abstract

We present resolved [CI] line intensities of 18 nearby galaxies observed with the SPIRE FTS spectrometer on the Herschel Space Observatory. We use these data along with resolved CO line intensities from $J_{\mathrm{up}}=1$ to 7 to interpret what phase of the interstellar medium the [CI] lines trace within typical local galaxies. A tight, linear relation is found between the intensities of the CO(4-3) and [CI](2-1) lines; we hypothesize this is due to the similar upper level temperature of these two lines. We modeled the [CI] and CO line emission using large velocity gradient models combined with an empirical template. According to this modeling, the [CI](1-0) line is clearly dominated by the low-excitation component. We determine [CI] to molecular mass conversion factors for both the [CI](1-0) and [CI](2-1) lines, with mean values of ${\alpha }_{[\mathrm{CI}](1-0)}=7.3$ M${}_{\mathrm{sun}}$ K${}^{-1}$ km${}^{-1}$ s pc${}^{-2}$ and ${\alpha }_{[\mathrm{CI}](2-1)}=34$ M${}_{\mathrm{sun}}$ K${}^{-1}$ km${}^{-1}$ s pc${}^{-2}$ with logarithmic root-mean-square spreads of 0.20 and 0.32 dex, respectively. The similar spread of ${\alpha }_{[\mathrm{CI}](1-0)}$ to ${\alpha }_{\mathrm{CO}}$ (derived using the CO(2-1) line) suggests that [CI](1-0) may be just as good a tracer of cold molecular gas as CO(2-1) in galaxies of this type. On the other hand, the wider spread of ${\alpha }_{[\mathrm{CI}](2-1)}$ and the tight relation found between [CI](2-1) and CO(4-3) suggest that much of the [CI](2-1) emission may originate in warmer molecular gas.

arXiv comment15 pages, 10 figures, published in ApJ

References in corpus (34)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Herschel-SPIRE instrument and its in-flight performance
• The CO-to-H2 Conversion Factor
• A computer program for fast non-LTE analysis of interstellar line spectra
• Cool Gas in High Redshift Galaxies
• The Atlas3D project - XV. Benchmark for early-type galaxies scaling relations from 260 dynamical models: mass-to-light ratio, dark matter, Fundamental Plane and Mass Plane
• Molecular Gas and Star Formation in Nearby Disk Galaxies
• The CO-to-H2 Conversion Factor and Dust-to-Gas Ratio on Kiloparsec Scales in Nearby Galaxies
• Optical Spectroscopy and Nebular Oxygen Abundances of the Spitzer/SINGS Galaxies
• The BIMA Survey of Nearby Galaxies (BIMA SONG). II. The CO Data
• KINGFISH -- Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel: Survey Description and Image Atlas
• Nobeyama CO Atlas of Nearby Spiral Galaxies: Distribution of Molecular Gas in Barred and Non-barred Spiral Galaxies
• A Survey of Atomic Carbon at High Redshift
• L'CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive
• The Spatially Resolved [CII] Cooling Line Deficit in Galaxies
• CI emission in Ultra Luminous Infrared Galaxies as a molecular gas mass tracer
• Tracing the formation of molecular clouds via [CII], [CI] and CO emission
• Atomic Carbon in Galaxies
• A Herschel Space Observatory Spectral Line Survey of Local Luminous Infrared Galaxies from 194 to 671 Microns
• Modelling [CI] emission from turbulent molecular clouds
• The JCMT Nearby Galaxies Legacy Survey VIII. CO data and the L(CO3-2)-L(FIR) correlation in the SINGS sample
• An Alternative Accurate Tracer of Molecular Clouds: The "$X_{\mathrm{CI}}$-Factor"
• A Survey of the Molecular ISM Properties of Nearby Galaxies using the Herschel FTS
• Neutral carbon and CO in 76 (U)LIRGs and starburst galaxy centers A method to determine molecular gas properties in luminous galaxies
• Discovery of Nuclear X-ray Sources in SINGS Galaxies
• Neutral Carbon Emission in luminous infrared galaxies The \CI\ Lines as Total Molecular Gas Tracers
• Shock Excited Molecules in NGC 1266: ULIRG conditions at the center of a Bulge Dominated Galaxy
• Resolved neutral carbon emission in nearby galaxies: [CI] Lines as Total Molecular Gas Tracers
• NGC1266 as a Local Candidate for Rapid Cessation of Star Formation
• Extensive [CI] Mapping toward the Orion-A Molecular Cloud
• Black Holes in Bulgeless Galaxies: An XMM-Newton Investigation of NGC 3367 and NGC 4536
• Spatially resolved physical conditions of molecular gas and potential star formation tracers in M83, revealed by the Herschel SPIRE FTS
• Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud. I. N159W
• Probing the cold and warm molecular gas in the Whirlpool Galaxy: Herschel SPIRE-FTS Observations of the central region of M51 (NGC 5194)

Cited by in corpus (20)

• Cool Outflows in Galaxies and their Implications
• Turbulent Gas in Lensed Planck-selected Starbursts at redshifts 1-3.5
• A dusty compact object bridging galaxies and quasars at cosmic dawn
• Dust, CO and [CI]: Cross-calibration of molecular gas mass tracers in metal-rich galaxies across cosmic time
• Photodissociation Region Diagnostics Across Galactic Environments
• ALMA Observations of Multiple-CO and C Lines Toward the Active Galactic Nucleus of NGC 7469: X-Ray-dominated Region Caught in the Act
• Cold gas disks in main-sequence galaxies at cosmic noon: Low turbulence, flat rotation curves, and disk-halo degeneracy
• Direct measurement of the [CI] luminosity to molecular gas mass conversion factor in high-redshift star-forming galaxies
• Dust continuum, CO, and [C I] 1-0 lines: self-consistent H2 mass estimates and the possibility of globally CO-dark galaxies at $z=0.35$
• The subthermal excitation of the C{\sc i} lines in the molecular gas reservoirs of galaxies: its significance and potential utility
• PHANGS-JWST First Results: Stellar Feedback-Driven Excitation and Dissociation of Molecular Gas in the Starburst Ring of NGC 1365?
• The Carbon-to-H${}_2$, CO-to-H${}_2$ Conversion Factors and Carbon Abundance on Kiloparsec Scales in Nearby Galaxies
• An ACA Survey of [CI] ${}^3{P}_1{-}^3{P}_0$, CO $J=4-3$, and Dust Continuum in Nearby U/LIRG
• Discovery of a [CI]-faint, CO-bright Galaxy: ALMA Observations of the Merging Galaxy NGC 6052
• Molecular gas properties of Q1700-MD94: a massive, main-sequence galaxy at $z\approx 2$
• Molecular gas budget and characterization of intermediate-mass star-forming galaxies at $z\approx 2-3$
• Gas and Star Formation from HD and Dust Emission in a Strongly Lensed Galaxy
• CI and CO in Nearby Spiral Galaxies -- I. Line Ratio and Abundance Variations at ~ 200 pc Scales
• Metallicity dependence of the CO-to-H${}_2$ and the [CI]-to-H${}_2$ conversion factors in galaxies
• Atomic Carbon [CI]${(}^3{P}_1{-}^3{P}_0)$ Mapping of the Nearby Galaxy M83