Radiative transfer meets Bayesian statistics: where does a galaxy's [CII] emission come from?

Abstract

The [CII] 158$\mu$m emission line can arise in all phases of the ISM, therefore being able to disentangle the different contributions is an important yet unresolved problem when undertaking galaxy-wide, integrated [CII] observations. We present a new multi-phase 3D radiative transfer interface that couples Starburst99, a stellar spectrophotometric code, with the photoionisation and astrochemistry codes Mocassin and 3D-PDR. We model entire star forming regions, including the ionised, atomic and molecular phases of the ISM, and apply a Bayesian inference methodology to parametrise how the fraction of the [CII] emission originating from molecular regions, $f_{[CII],mol}$, varies as a function of typical integrated properties of galaxies in the local Universe. The main parameters responsible for the variations of $f_{[CII],mol}$ are specific star formation rate (sSFR), gas phase metallicity, HII region electron number density ($n_e$), and dust mass fraction. For example, $f_{[CII],mol}$ can increase from 60% to 80% when either $n_e$ increases from 10${}^{1.5}$ to 10${}^{2.5}$cm${}^{-3}$, or SSFR decreases from $10^{-9.6}$ to $10^{-10.6}$ yr${}^{-1}$. Our model predicts for the Milky Way that $f_{[CII],mol}$$=75.8\pm 5.9$%, in agreement with the measured value of 75%. When applying the new prescription to a complete sample of galaxies from the Herschel Reference Survey (HRS), we find that anywhere from 60 to 80% of the total integrated [CII] emission arises from molecular regions.

arXiv comment17 pages including appendices, 14 figures, 3 tables, Accepted for publication in MNRAS

References in corpus (75)

• Galactic Stellar and Substellar Initial Mass Function
• On the variation of the Initial Mass Function
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• The Host Galaxies of AGN
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• The physical properties of star forming galaxies in the low redshift universe
• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• The reversal of the star formation-density relation in the distant universe
• Multiwavelength study of massive galaxies at z~2. I. Star formation and galaxy growth
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• Astrophysics Source Code Library
• The UMIST database for astrochemistry 2012
• Modeling the Panchromatic Spectral Energy Distributions of Galaxies
• Far Infrared and Submillimeter Emission from Galactic and Extragalactic Photo-Dissociation Regions
• The CO-to-H2 Conversion Factor From Infrared Dust Emission Across the Local Group
• An Analytic Model for the Evolution of the Stellar, Gas, and Metal Content of Galaxies
• Optimization of Starburst99 for Intermediate-Age and Old Stellar Populations
• The 2013 Release of Cloudy
• A 158 Micron [CII] Line Survey of Galaxies at z ~ 1 to 2: An Indicator of Star Formation in the Early Universe
• A Herschel [CII] Galactic plane survey I: the global distribution of ISM gas components
• Galaxy Evolution in Cosmological Simulations With Outflows I: Stellar Masses and Star Formation Rates
• A Library of Theoretical Ultraviolet Spectra of Massive, Hot Stars for Evolutionary Synthesis
• The Herschel Reference Survey
• The Characteristic Star Formation Histories of Galaxies at Redshifts z~2-7
• The Magellanic Mopra Assessment (MAGMA). I. The Molecular Cloud Population of the Large Magellanic Cloud
• The PdBI Arcsecond Whirlpool Survey (PAWS): Environmental Dependence of Giant Molecular Cloud Properties in M51
• Mocassin: A fully three-dimensional Monte Carlo photoionization code
• The assembly of "normal" galaxies at z=7 probed by ALMA
• The dust scaling relations of the Herschel Reference Survey
• ALMA Imaging of Gas and Dust in a Galaxy Protocluster at Redshift 5.3: [CII] Emission in "Typical" Galaxies and Dusty Starbursts ~1 Billion Years after the Big Bang
• A deep submillimetre survey of the Galactic Centre
• The dusty MOCASSIN: fully self-consistent 3D photoionisation and dust radiative transfer models
• The SAMI Galaxy Survey: Shocks and Outflows in a normal star-forming galaxy
• A Comparative Study of Giant Molecular Clouds in M51, M33 and the Large Magellanic Cloud
• [CII] 158$\mu$m Emission and Metallicity in PDRs
• A cosmic-ray dominated ISM in Ultra Luminous Infrared Galaxies: new initial conditions for star formation
• Type Ia Supernova Light Curve Inference: Hierarchical Models in the Optical and Near Infrared
• Collisional Excitation of the [CII] Fine Structure Transition in Interstellar Clouds
• C, N, O Abundances in the Most Metal-Poor Damped Lyman alpha Systems
• A Herschel [C II] Galactic plane survey II: CO-dark H2 in clouds
• The reliability of [CII] as a star formation rate indicator
• Detection of the 205 um [NII] Line from the Carina Nebula
• C${}^{+}$ detection of warm dark gas in diffuse clouds
• The H II Region/PDR Connection: Self-Consistent Calculations of Physical Conditions in Star-Forming Regions
• Molecular line intensities as measures of cloud masses - I. Sensitivity of CO emissions to physical parameter variations
• 3D-PDR: A new three-dimensional astrochemistry code for treating Photodissociation Regions
• PACS photometry of the Herschel Reference Survey - Far-infrared/sub-millimeter colours as tracers of dust properties in nearby galaxies
• The Massive Star Forming Region Cygnus OB2. II. Integrated Stellar Properties and the Star Formation History
• ALMA Observation of 158 micron [CII] Line and Dust Continuum of a z=7 Normally Star-forming Galaxy in the Epoch of Reionization
• The nature of the interstellar medium of the starburst low-metallicity galaxy Haro11: a multi-phase model of the infrared emission
• The size--density relation of extragalactic HII regions
• VLT spectroscopy of low-metallicity emission-line galaxies: abundance patterns and abundance discrepancies
• Evidence for a non-universal Kennicutt-Schmidt relationship using hierarchical Bayesian linear regression
• An Alternative Accurate Tracer of Molecular Clouds: The "$X_{\mathrm{CI}}$-Factor"
• A 3D Monte Carlo Photoionization Code for Modeling Diffuse Ionized Gas
• Self-Consistent Dynamic Models of Steady Ionization Fronts I. Weak-D and Weak-R Fronts
• [CII] observations of H${}_2$ molecular layers in transition clouds
• The Herschel M33 extended survey (HerM33es): PACS spectroscopy of the star forming region BCLMP 302
• Halpha Imaging of the Herschel Reference Survey. The star formation properties of a volume-limited, K-band-selected sample of nearby late-type galaxies
• Evidence for Grain Growth in Molecular Clouds: A Bayesian Examination of the Extinction Law in Perseus
• TORUS-3DPDR: A self-consistent code treating three-dimensional photoionization and photodissociation regions
• Insights into gas heating and cooling in the disc of NGC 891 from Herschel far-infrared spectroscopy
• Synthetic observations of simulated pillars of creation
• Gas and dust cooling along the major axis of M33 (HerM33es): ISO/LWS CII observations
• The Gini Coefficient as a Tool for Image Family Idenitification in Strong Lensing Systems with Multiple Images
• A multiwavelength study of the Magellanic-type galaxy NGC 4449 - I. Modelling the spectral energy distribution, the ionization structure and the star formation history
• SImulator of GAlaxy Millimetre/submillimetre Emission (SIGAME): CO emission from massive z=2 main-sequence galaxies
• Velocity resolved [CII] spectroscopy of the center and the BCLMP302 region of M33 (HerM33es)
• A Photodissociation Region study of NGC 4038
• Understanding the Formation and Evolution of Interstellar Ices: A Bayesian Approach
• A spectral and photometric study of 102 star forming regions in seven spiral galaxies
• Mapping CS in Starburst Galaxies: Disentangling and Characterising Dense Gas

Cited by in corpus (31)

• A Herschel/PACS Far Infrared Line Emission Survey of Local Luminous Infrared Galaxies
• The [C II] emission as a molecular gas mass tracer in galaxies at low and high redshift
• High-redshift star formation in the ALMA era
• Tracing the total molecular gas in galaxies: [CII] and the CO-dark gas
• Deriving a multivariate CO-to-H${}_2$ conversion function using the [CII]/CO(1-0) ratio and its application to molecular gas scaling relations
• The ALPINE-ALMA [CII] survey: Molecular gas budget in the Early Universe as traced by [CII]
• The Herschel Dwarf Galaxy Survey: II. Physical conditions, origin of [CII] emission, and porosity of the multiphase low-metallicity ISM
• SIGAME simulations of the [CII], [OI] and [OIII] line emission from star forming galaxies at z ~ 6
• Photodissociation Region Diagnostics Across Galactic Environments
• The Physical Drivers and Observational Tracers of CO-to-H2 Conversion Factor Variations in Nearby Barred Galaxy Centers
• Tracing Molecular Gas in z $\simeq$ 6 Galaxies with [C$\mathrm{II}$]
• The ALPINE-ALMA [CII] survey: Small Lya-[CII] velocity offsets in main-sequence galaxies at 4.4 < z < 6
• Synthetic observations of star formation and the interstellar medium
• Synthetic [CII] emission maps of a simulated molecular cloud in formation
• PDFchem: A new fast method to determine ISM properties and infer environmental parameters using probability distributions
• SOFIA/FIFI-LS Full-disk [CII] Mapping and CO-dark Molecular Gas across the Nearby Spiral Galaxy NGC 6946
• Dark Molecular Gas in Simulations of z~0 Disc Galaxies
• The impact of cosmic-ray attenuation on the carbon cycle emission in molecular clouds
• The origin of the [CII]-deficit in a simulated dwarf galaxies starburst
• Herschel Spectroscopy of Early Type Galaxies
• Revisiting the [C II]${}_{158\mu \text{m}}$ line-intensity mapping power spectrum from the EoR using non-uniform line-luminosity scatter
• Extremely weak CO emission in IZw 18
• The Dense Warm Ionized Medium in the Inner Galaxy
• Metallicity dependence of the CO-to-H${}_2$ and the [CI]-to-H${}_2$ conversion factors in galaxies
• Centrally concentrated molecular gas driving galactic-scale ionised gas outflows in star-forming galaxies
• Ionized Carbon in Galaxies: The [C II] 158 $\mu$m Line as a Total Molecular Gas Mass Tracer Revisited
• Herschel 158$\mu$m [CII] Observations of "CO-dark" Gas in the Perseus Giant Molecular Cloud
• Disentangling emission from star-forming regions in the Magellanic Clouds: Linking [OIII]88 micron and 24 micron
• Full disc [CII] mapping of nearby star-forming galaxies: SOFIA FIFI/LS observations of NGC 3627, NGC 4321, and NGC 6946
• Bright [CII]158$\mu$m Streamers as a Beacon for Giant Galaxy Formation in SPT2349$-$56 at $z=4.3$
• Tight correlation of star formation with [Ci] and CO lines across cosmic time