Spatial fluctuations of the intergalactic temperature-density relation after hydrogen reionization

Abstract

The thermal state of the post-reionization IGM is sensitive to the timing of reionization and the nature of the ionizing sources. We have modelled here the thermal state of the IGM in cosmological radiative transfer simulations of a realistic, extended, spatially inhomogeneous hydrogen reionization process, carefully calibrated with Ly-alpha forest data. We compare these with cosmological simulations run using a spatially homogeneous ionizing background. The simulations with a realistic growth of ionized regions and a realistic spread in reionization redshifts show, as expected, significant spatial fluctuations in the temperature-density relation (TDR) of the post-reionization IGM. The most recently ionized regions are hottest and exhibit a flatter TDR. In simulations consistent with the average TDR inferred from Ly-alpha forest data, these spatial fluctuations have a moderate but noticeable effect on the statistical properties of the Ly-alpha opacity of the IGM at z ~ 4-6. This should be taken into account in accurate measurements of the thermal properties of the IGM and the free-streaming of dark matter from Ly-alpha forest data in this redshift range. The spatial variations of the TDR predicted by our simulations are, however, smaller by about a factor two than would be necessary to explain the observed large spatial opacity fluctuations on large (> 50 comoving Mpc/h) scales at z > 5.5.

17 pages, 11 figures. Accepted to MNRAS

References in corpus (13)

• Ultralight scalars as cosmological dark matter
• Evidence of patchy hydrogen reionization from an extreme Ly$\alpha$ trough below redshift six
• 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
• Inside-out or Outside-in: The topology of reionization in the photon-starved regime suggested by Lyman-alpha forest data
• The nature and evolution of the highly ionized near-zones in the absorption spectra of z~6 quasars
• Imprint of Inhomogeneous Hydrogen Reionization on the Temperature Distribution of the Intergalactic Medium
• Voigt Profile Fitting to Quasar Absorption Lines: An Analytic Approximation to the Voigt-Hjerting Function
• Self-Consistent Modeling of Reionization in Cosmological Hydrodynamical Simulations
• Multi-frequency, thermally coupled radiative transfer with TRAPHIC: Method and tests
• Observations of the Lyman series forest towards the redshift 7.1 quasar ULAS J1120+0641
• Exploring the Thermal State of the Low-Density Intergalactic Medium at z=3 with an Ultra-High Signal-to-Noise QSO Spectrum
• On Modeling and Measuring the Temperature of the z~5 IGM
• Probing the Epoch of Reionization with the Lyman Alpha Forest at z~4-5

Cited by in corpus (50)

• Wave Dark Matter
• Hydrogen reionisation ends by $z=5.3$: Lyman-$\alpha$ optical depth measured by the XQR-30 sample
• Large Lyman-alpha opacity fluctuations and low CMB tau in models of late reionization with large islands of neutral hydrogen extending to z<5.5
• New constraints on Lyman-α opacity with a sample of 62 quasars at z > 5.7
• Consistent modelling of the meta-galactic UV background and the thermal/ionization history of the intergalactic medium
• Long troughs in the Lyman-$\alpha$ forest below redshift 6 due to islands of neutral hydrogen
• The Opacity of the Intergalactic Medium Measured Along Quasar Sightlines at $z\sim 6$
• Probing the thermal state of the intergalactic medium at $z>5$ with the transmission spikes in high-resolution Ly$\alpha$ forest spectra
• The THESAN project: properties of the intergalactic medium and its connection to Reionization-era galaxies
• Reionization and galaxy inference from the high-redshift Lyα forest
• Constraining Non-Cold Dark Matter Models with the Global 21-cm Signal
• How to Quench a Dwarf Galaxy: The Impact of Inhomogeneous Reionization on Dwarf Galaxies and Cosmic Filaments
• Evidence for Large-Scale Fluctuations in the Metagalactic Ionizing Background Near Redshift Six
• XQR-30: the ultimate XSHOOTER quasar sample at the reionization epoch
• Reionization in Technicolor
• The Role of Galaxies and AGN in Reionising the IGM - I: Keck Spectroscopy of 5 < z < 7 Galaxies in the QSO Field J1148+5251
• Heating of the Intergalactic Medium by Hydrogen Reionization
• The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium
• Constraining the second half of reionization with the Lyman-$\beta$ forest
• Inhomogeneous Reionization Models in Cosmological Hydrodynamical Simulations
• Imprints of temperature fluctuations on the $z\sim 5$ Lyman-$\alpha$ forest: a view from radiation-hydrodynamic simulations of reionization
• Large scale simulations of H and He reionization and heating driven by stars and more energetic sources
• The Evolution of the HeII-Ionizing Background at Redshifts 2.3<z<3.8 Inferred from a Statistical Sample of 24 HST/COS HeII Ly$\alpha$ Absorption Spectra
• Inferring the Thermal History of the Intergalactic Medium from the Properties of the Hydrogen and Helium Lyman-alpha Forest
• The Lyman Continuum Escape Fraction of Galaxies and AGN in the GOODS Fields
• Dark-ages Reionization and Galaxy Formation Simulation XX. The Ly$\alpha$ IGM transmission properties and environment of bright galaxies during the Epoch of Reionization
• Anomaly in the Opacity of the Post-Reionization Intergalactic Medium in the Ly$\alpha$ and Ly$\beta$ Forest
• A high space density of L* Active Galactic Nuclei at z~4 in the COSMOS field
• The effect of inhomogeneous reionisation on the Lyman-$\alpha$ forest power spectrum at redshift $z>4$: implications for thermal parameter recovery
• Effect of non-equilibrium ionization on derived physical conditions of the high-$z$ intergalactic medium
• Faint LAEs near z>4.7 CIV absorbers revealed by MUSE
• Impact of inhomogeneous reionization on the Lyman-α forest
• The influence of metagalactic ultra-violet background fluctuations on the high-redshift Ly$\alpha$ forest
• Constraining the reionization and thermal history of the Universe using a semi-numerical photon-conserving code SCRIPT
• The detectability of strong 21 centimetre forest absorbers from the diffuse intergalactic medium in late reionisation models
• Revised estimates of CMB $B$-mode polarization induced by patchy reionization
• On the accuracy of common moment-based radiative transfer methods for simulating reionization
• Late-end reionization with ATON-HE: towards constraints from Lyman-$\alpha$ emitters observed with JWST
• Possible evidence for a large-scale enhancement in the Lyman-$\alpha$ forest power spectrum at redshift $\text{z}\ge 4$
• Implications of the $z>5$ Lyman-$\alpha$ forest for the 21-cm power spectrum from the epoch of reionization
• A fast method of reionization parameter space exploration using GPR trained SCRIPT
• A CRASH simulation of the contribution of binary stars to the epoch of reionization
• Probing patchy reionisation with JWST: IGM opacity constraints from the Lyman-$\alpha$ forest of galaxies in legacy extragalactic fields
• Probing Large Scale Ionizing Background Fluctuation with Lyman $\alpha$ Forest and Galaxy Cross-correlation at z=2.4
• Dark-Ages Reionisation & Galaxy Formation Simulation XVI: The Thermal Memory of Reionisation
• Prospects of FRBs and Large Scale 21 cm Power Spectra in Constraining the Epoch of Reionization
• Photometric IGM tomography with Subaru/HSC: the large-scale structure of Ly$\alpha$ emitters and IGM transmission in the COSMOS field at $z\sim 5$
• The THESAN project: environmental drivers of Local Group reionization
• Efficient Modelling of Lyman-α opacity fluctuations during late reionization epoch
• The effect of helium reionization on the Lyman-alpha forest hydrogen flux statistics