[CII] 158$\mu$m Emission and Metallicity in PDRs

Abstract

We study the effects of a metallicity variation on the thermal balance and [CII] fine-structure line strengths in interstellar photon dominated regions (PDRs). We find that a reduction in the dust-to-gas ratio and the abundance of heavy elements in the gas phase changes the heat balance of the gas in PDRs. The surface temperature of PDRs decreases as the metallicity decreases except for high density ($n>10^6$ cm${}^{-3}$) clouds exposed to weak ($\chi <100$) FUV fields where vibrational H${}_2$-deexcitation heating dominates over photoelectric heating of the gas. We incorporate the metallicity dependence in our KOSMA-$\tau$ PDR model to study the metallicity dependence of [CII]/CO line ratios in low metallicity galaxies. We find that the main trend in the variation of the observed CII/CO ratio with metallicity is well reproduced by a single spherical clump, and does not necessarily require an ensemble of clumps as in the semi-analytical model presented by Bolatto et al. (1999).

16 pages, 14 figures, accepted by A&A

Cited by in corpus (57)

• The Resolved Properties of Extragalactic Giant Molecular Clouds
• The Herschel Dwarf Galaxy Survey: I. Properties of the low-metallicity ISM from PACS spectroscopy
• Photodissociation and X-Ray Dominated Regions
• The chemistry of ions in the Orion Bar I. - CH+, SH+, and CF+: The effect of high electron density and vibrationally excited H2 in a warm PDR surface
• Water vapor distribution in protoplanetary disks
• SIGAME simulations of the [CII], [OI] and [OIII] line emission from star forming galaxies at z ~ 6
• Global Hydromagnetic Simulations of Protoplanetary Disks with Stellar Irradiation and Simplified Thermochemistry
• Electron Excitation of High Dipole Moment Molecules Reexamined
• FEEDBACK: a SOFIA Legacy Program to Study Stellar Feedback in Regions of Massive Star Formation
• Multidimensional chemical modelling, II. Irradiated outflow walls
• A clumpy-cloud PDR model of the global far-infrared line emission of the Milky Way
• Photodissociation Region Diagnostics Across Galactic Environments
• Full SED fitting with the KOSMA-τ PDR code - I. Dust modelling
• Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions
• The CO-dark molecular gas mass in 30 Doradus
• Radiative transfer meets Bayesian statistics: where does a galaxy's [CII] emission come from?
• Submillimeter Line Emission from LMC N159W: a Dense, Clumpy PDR in a Low Metallicity Environment
• Clumpy photon-dominated regions in Carina. I. [CI] and mid-J CO lines in two 4'x4' fields
• Chemical Abundances in a Turbulent Medium -- H${}_2$, OH${}^{+}$, H${}_2$O${}^{+}$, ArH${}^{+}$
• The interstellar medium of the Antennae Galaxies
• Modelling the ArH${}^{+}$ emission from the Crab Nebula
• Chemulator: Fast, accurate thermochemistry for dynamical models through emulation
• Probing multiphase gas in local massive elliptical galaxies via multiwavelength observations
• Mid-J CO observations of Perseus B1-East 5: evidence for turbulent dissipation via low-velocity shocks
• Atomic and molecular gas from the epoch of reionization down to redshift 2
• ALMA detection of [CII] 158 micron emission from a strongly lensed z=2 star-forming galaxy
• The PDR structure and kinematics around the compact HII regions S235A and S235C with [CII], [13CII], [OI] and HCO+ line profiles
• The co-evolution of molecular hydrogen and the grain size distribution in an isolated galaxy
• The SOFIA FEEDBACK Legacy Survey: Dynamics and mass ejection in the bipolar HII region RCW 36
• Study of Photon Dominated Regions in Cepheus B
• The KOSMA-$\tau$ PDR Model -- I. Recent updates to the numerical model of photo-dissociated regions
• HI-to-H${}_2$ Transitions in Dust-Free Interstellar Gas
• The Baryonic Collapse Efficiency of Galaxy Groups in the RESOLVE and ECO Surveys
• The Photon Dominated Region in the IC 348 molecular cloud
• Herschel PACS and SPIRE spectroscopy of the Photodissociation Regions associated with S 106 and IRAS 23133+6050
• First detection of [13CII] in the Large Magellanic Cloud
• Diagnosing the interstellar medium of galaxies with far-infrared emission lines I. The [C II] 158 microns line at z~0
• Photon Dominated Regions in NGC 3603
• The physical characteristics of the gas in the disk of Centaurus A using the Herschel Space Observatory
• Globules and pillars in Cygnus X III. Herschel and upGREAT/SOFIA far-infrared spectroscopy of the globule IRAS 20319+3958 inCygnus X
• Photon-Dominated Region Modeling of the [C I],[C II], and CO Line Emission from a Boundary in the Taurus Molecular Cloud
• Extremely weak CO emission in IZw 18
• Calibration of mid- to far-infrared spectral lines in galaxies
• CO emission from candidate photo-dissociation regions in M81
• ALMA Lensing Cluster Survey: A spectral stacking analysis of [CII] in lensed $z\sim 6$ galaxies
• Ionised carbon and galaxy activity
• A PDR model for the FIR mid-$J$ CO ladder with universal rotational temperature in star forming region
• Photoelectric heating effects on the evolution of luminous disk galaxies
• A Herschel mapping of [C ii], [O i] and [O iii] lines from the circumnuclear region of M31
• Molecular Cloud Matching in CO and Dust in M33 I. High-Resolution Hydrogen Column Density Maps from Herschel
• Disentangling emission from star-forming regions in the Magellanic Clouds: Linking [OIII]88 micron and 24 micron
• "Dust Giant": Extended and Clumpy Star-Formation in a Massive Dusty Galaxy at $z=1.38$
• The origin and evolution of the [CII] deficit in HII regions and star-forming molecular clouds
• Molecular cloud matching in CO and dust in M33 II. Physical properties of giant molecular clouds
• Extended atomic carbon around molecular clouds
• Stellar feedback and triggered star formation in the prototypical bubble RCW 120
• Metallicity Effects in PDRs