Clumping factors of HII, HeII and HeIII

Abstract

Estimating the intergalactic medium ionization level of a region needs proper treatment of the reionization process for a large representative volume of the universe. The clumping factor, a parameter which accounts for the effect of recombinations in unresolved, small-scale structures, aids in achieving the required accuracy for the reionization history even in simulations with low spatial resolution. In this paper, we study for the first time the redshift evolution of clumping factors of different ionized species of H and He in a small but very high resolution simulation of the reionization process. We investigate the dependence of the value and redshift evolution of clumping factors on their definition, the ionization level of the gas, the grid resolution, box size and mean dimensionless density of the simulations.

arXiv comment12 pages, 10 figures, 1 table. Accepted by MNRAS

References in corpus (35)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The cosmological simulation code GADGET-2
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• Radiative Transfer in a Clumpy Universe: III. The Nature of Cosmological Ionizing Sources
• Merger rates in hierarchical models of galaxy formation. II: Comparison with N-body simulations
• The Rest-Frame Extreme Ultraviolet Spectral Properties of QSOs
• Reionization of the Universe and the Early Production of Metals
• Reionization of the Inhomogeneous Universe
• A Survey of z>5.7 Quasars in the Sloan Digital Sky Survey IV: Discovery of Seven Additional Quasars
• Reionization and Cosmology with 21 cm Fluctuations
• The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization
• The morphology of HII regions during reionization
• The First Cosmic Structures and their Effects
• Model-independent insights into the nature of the Lyman-alpha forest and the distribution of matter in the universe
• Unusually Large Fluctuations in the Statistics of Galaxy Formation at High Redshift
• Keeping the Universe ionised: Photo-heating and the clumping factor of the high-redshift intergalactic medium
• Radiative transfer simulations of cosmic reionization I: methodology and initial results
• Self-regulated reionization
• Cosmological Reionization Around the First Stars: Monte Carlo Radiative Transfer
• On Lyman-limit Systems and the Evolution of the Intergalactic Ionizing Background
• CRASH: a Radiative Transfer Scheme
• A Size of ~10 Mpc for the Ionized Bubbles at the End of Cosmic Reionization
• The Physics and Early History of the Intergalactic Medium
• The Impact of Small-Scale Structure on Cosmological Ionization Fronts and Reionization
• Large-Scale Simulations of Reionization
• Direct Numerical Simulation of Reionization II: Recombinations, Clumping Factors, and the Photon Budget for Reionization
• Multi-frequency, thermally coupled radiative transfer with TRAPHIC: Method and tests
• The effect of intergalactic helium on hydrogen reionisation: implications for the sources of ionising photons at z > 6
• CRASH2: colored packets and other updates
• The Opacity of the Intergalactic Medium During Reionization: Resolving Small-Scale Structure
• CRASH3: cosmological radiative transfer through metals
• Recombination clumping factor during cosmic reionization
• Redshifted 21 cm Emission From the Pre-Reionization Era II. HII Regions Around Individual Quasars
• Modelling recombinations during cosmological reionization
• Enabling parallel computing in CRASH

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• A Cosmic UV/X-ray Background Model Update
• Reionization and high-redshift galaxies: the view from quasar absorption lines
• Hydrogen Reionization in the Illustris universe
• Cosmic Reionization After Planck and Before JWST: An Analytic Approach
• The impact of inhomogeneous subgrid clumping on cosmic reionization
• Cosmic Reionization On Computers III. The Clumping Factor
• The Infrared Medium-deep Survey. VIII. Quasar Luminosity Function at $z\sim 5$
• The Faint Host Galaxies of C IV Absorbers at z > 5
• The impact of inhomogeneous subgrid clumping on cosmic reionization II: modelling stochasticity
• Helium Reionization Simulations. I. Modeling Quasars as Radiation Sources
• SCORCH. III. Analytical Models of Reionization with Varying Clumping Factors