The accuracy of semi-numerical reionization models in comparison with radiative transfer simulations

Abstract

We have developed a modular semi-numerical code that computes the time and spatially dependent ionization of neutral hydrogen (HI), neutral (HeI) and singly ionized helium (HeII) in the intergalactic medium (IGM). The model accounts for recombinations and provides different descriptions for the photoionization rate that are used to calculate the residual HI fraction in ionized regions. We compare different semi-numerical reionization schemes to a radiative transfer (RT) simulation. We use the RT simulation as a benchmark, and find that the semi-numerical approaches produce similar HII and HeII morphologies and power spectra of the HI 21cm signal throughout reionization. As we do not track partial ionization of HeII, the extent of the double ionized helium (HeIII) regions is consistently smaller. In contrast to previous comparison projects, the ionizing emissivity in our semi-numerical scheme is not adjusted to reproduce the redshift evolution of the RT simulation, but directly derived from the RT simulation spectra. Among schemes that identify the ionized regions by the ratio of the number of ionization and absorption events on different spatial smoothing scales, we find those that mark the entire sphere as ionized when the ionization criterion is fulfilled to result in significantly accelerated reionization compared to the RT simulation. Conversely, those that flag only the central cell as ionized yield very similar but slightly delayed redshift evolution of reionization, with up to 20% ionizing photons lost. Despite the overall agreement with the RT simulation, our results suggests that constraining ionizing emissivity sensitive parameters from semi-numerical galaxy formation-reionization models are subject to photon nonconservation.

arXiv comment21 pages, 11 Figures, accepted for publication in MNRAS

References in corpus (70)

• The cosmological simulation code GADGET-2
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ~ 6 Quasars II: A Sample of 19 Quasars
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• Ahf: Amiga's Halo Finder
• 21cmFAST: A Fast, Semi-Numerical Simulation of the High-Redshift 21-cm Signal
• The Growth of HII Regions During Reionization
• Massloss of galaxies due to a UV-background
• On the evolution of the HI column density distribution in cosmological simulations
• Reionization of the Inhomogeneous Universe
• Efficient Simulations of Early Structure Formation and Reionization
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• Cosmological Reionization by Stellar Sources
• Escape fraction of ionizing photons during reionization: effects due to supernova feedback and runaway OB stars
• The morphology of HII regions during reionization
• 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
• Simulations and Analytic Calculations of Bubble Growth During Hydrogen Reionization
• Faint AGNs at z>4 in the CANDELS GOODS-S field: looking for contributors to the reionization of the Universe
• The z~6 Luminosity Function Fainter than -15 mag from the Hubble Frontier Fields: The Impact of Magnification Uncertainties
• Radiative transfer simulations of cosmic reionization I: methodology and initial results
• Planck intermediate results. XLVII. Planck constraints on reionization history
• Cosmic Dawn (CoDa): the First Radiation-Hydrodynamics Simulation of Reionization and Galaxy Formation in the Local Universe
• The First Billion Years Project: The escape fraction of ionizing photons in the epoch of reionization
• Comparison Of Reionization Models: Radiative Transfer Simulations And Approximate, Semi-Numeric Models
• The Lyman-Continuum Photon Production Efficiency xi_{ion} of z~4-5 Galaxies from IRAC-based Halpha Measurements: Implications for the Escape Fraction and Cosmic Reionization
• Can the intergalactic medium cause a rapid drop in Lyman alpha emission at z>6?
• Simulating cosmic reionization: How large a volume is large enough?
• Feedback-regulated star formation and escape of LyC photons from mini-haloes during reionisation
• Inside-out or Outside-in: The topology of reionization in the photon-starved regime suggested by Lyman-alpha forest data
• Inhomogeneous recombinations during cosmic reionization
• Cosmic Reionization On Computers I. Design and Calibration of Simulations
• Cosmological Reionization Around the First Stars: Monte Carlo Radiative Transfer
• Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
• Was the Universe Reionized by Massive Population-III Stars?
• Fast Large Volume Simulations of the 21 cm Signal from the Reionization and pre-Reionization Epochs
• A physical upper limit on the HI column density of gas clouds
• Accretion onto Intermediate Mass Black Holes Regulated by Radiative Feedback I. Parametric Study for Spherically Symmetric Accretion
• CRASH: a Radiative Transfer Scheme
• Dark-ages reionization and galaxy formation simulation - III. Modelling galaxy formation and the epoch of reionization
• Constraints on X-ray Emissions from the Reionization Era
• 21 cm signal from cosmic dawn: Imprints of spin temperature fluctuations and peculiar velocities
• Reionization on Large Scales I: A Parametric Model Constructed from Radiation-Hydrodynamic Simulations
• Fast Large-Scale Reionization Simulations
• Escape Fraction of Ionizing Radiation from Starburst Galaxies at High Redshifts
• Can 21-cm observations discriminate between high-mass and low-mass galaxies as reionization sources?
• On the use of semi-numerical simulations in predicting the 21-cm signal from the epoch of reionization
• On the Contribution of Active Galactic Nuclei to the High-Redshift Metagalactic Ionizing Background
• The Aurora radiation-hydrodynamical simulations of reionization: calibration and first results
• The systematic search for $z\gtrsim 5$ active galactic nuclei in the $Chandra$ Deep Field South
• Searching for the reionization sources
• Hydrogen Reionization in the Illustris universe
• 21-cm signal from cosmic dawn - II: Imprints of the light-cone effects
• The effect of intergalactic helium on hydrogen reionisation: implications for the sources of ionising photons at z > 6
• Simulating the 21-cm signal from reionisation including non-linear ionisations and inhomogeneous recombinations
• CRASH2: colored packets and other updates
• The Soft, Fluctuating UVB at $z\sim 6$ as Traced by C IV, SiIV, and CII
• Lyman-Alpha Emitting Galaxies as a Probe of Reionization: Large-Scale Bubble Morphology and Small-Scale Absorbers
• The Late Reionization of Filaments
• The visibility of Lyman Alpha Emitters: constraining reionization, ionizing photons and dust
• Exploring 21cm - Lyman Alpha emitter synergies for SKA
• Helium Reionization Simulations. II. Signatures of Quasar Activity on the IGM
• The Expected Mass Function for Low Mass Galaxies in a CDM Cosmology: Is There a Problem?
• Large 21 cm signals from AGN-dominated reionization
• Probing patchy reionization through tau-21cm correlation statistics
• Redshifted intergalactic 3He+ 8.7 GHz hyperfine absorption
• The Structure of Reionization in Hierarchical Galaxy Formation Models
• Probing large scale filaments with HI and ${}^3$HeII
• Helium Reionization Simulations. I. Modeling Quasars as Radiation Sources
• Enabling parallel computing in CRASH
• Semi-numeric simulations of helium reionization and the fluctuating radiation background

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• The signature of galaxy formation models in the power spectrum of the hydrogen 21cm line during reionization
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• Impact of 21-cm foreground mitigation strategies on reionization power spectrum constraints
• Nearest Neighbour-Based Statistics for 21cm-Galaxy Cross-Correlations in the Epoch of Reionization