The origin of the [CII]-deficit in a simulated dwarf galaxies starburst

Abstract

We present [CII] synthetic observations of smoothed particle hydrodynamics (SPH) simulations of a dwarf galaxy merger. The merging process varies the star-formation rate by more than three orders of magnitude. Several star clusters are formed, the feedback of which disperses and unbinds the dense gas through expanding HII regions and supernova (SN) explosions. For galaxies with properties similar to the modelled ones, we find that the [CII] emission remains optically thin throughout the merging process. We identify the Warm Neutral Medium ($3<\log T_{\mathrm{gas}}<4$ with ${\chi }_{\mathrm{HI}}>2{\chi }_{H2}$) to be the primary source of [CII] emission ($\sim 58\%$ contribution), although at stages when the HII regions are young and dense (during star cluster formation or SNe in the form of ionized bubbles) they can contribute $\gtrsim 50\%$ to the total [CII] emission. We find that the [CII]/FIR ratio decreases due to thermal saturation of the [CII] emission caused by strong FUV radiation fields emitted by the massive star clusters, leading to a [CII]-deficit medium. We investigate the [CII]-SFR relation and find an approximately linear correlation which agrees well with observations, particularly those from the Dwarf Galaxy Survey. Our simulation reproduces the observed trends of [CII]/FIR versus ${\Sigma }_{\mathrm{SFR}}$ and ${\Sigma }_{\mathrm{FIR}}$, and it agrees well with the Kennicutt relation of SFR-FIR luminosity. We propose that local peaks of [CII] in resolved observations may provide evidence for ongoing massive cluster formation.

To appear in ApJ. 24 pages, 17 figures. Comments welcome!

References in corpus (33)

• Array Programming with NumPy
• Cosmic Star Formation History
• The effect of photo-ionization on the cooling rates of enriched, astrophysical plasmas
• Simulating the formation of molecular clouds. I. Slow formation by gravitational collapse from static initial conditions
• A Compendium of Far-Infrared Line and Continuum Emission for 227 Galaxies Observed by the Infrared Space Observatory
• The Herschel Dwarf Galaxy Survey: I. Properties of the low-metallicity ISM from PACS spectroscopy
• [CII] 158 $\mu$m Emission as a Star Formation Tracer
• Tracing the total molecular gas in galaxies: [CII] and the CO-dark gas
• Effective destruction of CO by cosmic rays: implications for tracing H${}_2$ gas in the Universe
• Modelling Dust Evolution in Galaxies with a Multiphase, Inhomogeneous ISM
• A Herschel [CII] Galactic plane survey III: [CII] as a tracer of star formation
• The GRIFFIN project -- Formation of star clusters with individual massive stars in a simulated dwarf galaxy starburst
• The Spatially Resolved [CII] Cooling Line Deficit in Galaxies
• The Origins of [CII] Emission in Local Star-forming Galaxies
• 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
• A kiloparsec view of a typical star-forming galaxy when the Universe was ~1 Gyr old. Part I. Outflow, halo, and interstellar medium properties
• The formation of low metallicity globular clusters in dwarf galaxy mergers
• Strong FUV fields drive the [CII]/FIR deficit in z~3 dusty, star-forming galaxies
• Investigating H$\alpha$, UV, and IR star-formation rate diagnostics for a large sample of z ~ 2 galaxies
• Thermal and nonthermal dust sputtering in hydrodynamical simulations of the multiphase interstellar medium
• Photodissociation Region Diagnostics Across Galactic Environments
• The challenge of simulating the star cluster population of dwarf galaxies with resolved interstellar medium
• Radiative transfer meets Bayesian statistics: where does a galaxy's [CII] emission come from?
• Origin and z-distribution of Galactic diffuse [CII] emission
• Using [CII] 158 micron Emission From Isolated ISM Phases as a Star-Formation Rate Indicator
• Simulating the atomic and molecular content of molecular clouds using probability distributions of physical parameters
• [CII] $158\mu \mathrm{m}$ line emission from Orion A. I. A template for extragalactic studies?
• First detection of [13CII] in the Large Magellanic Cloud
• A Photodissociation Region study of NGC 4038
• The Dense Warm Ionized Medium in the Inner Galaxy
• The Case for Thermalization as a Contributor to the [CII] Deficit
• A panchromatic view of star cluster formation in a simulated dwarf galaxy starburst

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• The ALMA-CRISTAL survey: Dust temperature and physical conditions of the interstellar medium in a typical galaxy at z=5.66
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