All Outputs (76)

The origin of the characteristic shape and scatter of intergalactic damping wings during reionization (2024)
Journal Article

Ly α damping wings in the spectra of bright objects at high redshift are a useful probe of the ionization state of the intergalactic medium during the reionization epoch. It has recently been noted that, despite the inhomogeneous nature of reionizati... Read More about The origin of the characteristic shape and scatter of intergalactic damping wings during reionization.

Particle initialization effects on Lyman- αforest statistics in cosmological SPH simulations (2024)
Journal Article

Confronting measurements of the Lyman- αforest with cosmological hydrodynamical simulations has produced stringent constraints on models of particle dark matter and the thermal and ionization state of the intergalactic medium. We investigate the robu... Read More about Particle initialization effects on Lyman- αforest statistics in cosmological SPH simulations.

Unveiling dark matter free streaming at the smallest scales with the high redshift Lyman-alpha forest (2024)
Journal Article

This study introduces novel constraints on the free streaming of thermal relic warm dark matter (WDM) from Lyman-α forest flux power spectra. Our analysis utilizes a high resolution, high redshift sample of quasar spectra observed using the HIRES and... Read More about Unveiling dark matter free streaming at the smallest scales with the high redshift Lyman-alpha forest.

Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at 4.9≤z≤6.0 from a large sample of XShooter and ESI spectra (2023)
Journal Article

We measure the mean free path (⁠λmfp,HI⁠), photo-ionization rate (⁠⟨ΓHI⟩⁠) and neutral fraction (⁠⟨fHI⟩⁠) of hydrogen in 12 redshift bins at 4.85 < z < 6.05 from a large sample of moderate resolution XShooter and ESI QSO absorption spectra. The fluct... Read More about Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at 4.9≤z≤6.0 from a large sample of XShooter and ESI spectra.

Possible evidence for a large-scale enhancement in the Lyman-α forest power spectrum at redshift z ≥ 4 (2023)
Journal Article

Inhomogeneous reionization enhances the 1D Ly α forest power spectrum on large scales at redshifts z ≥ 4. This is due to coherent fluctuations in the ionized hydrogen fraction that arise from large-scale variations in the post-reionization gas temper... Read More about Possible evidence for a large-scale enhancement in the Lyman-α forest power spectrum at redshift z ≥ 4.

The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium (2022)
Journal Article

We present the Sherwood-Relics simulations, a new suite of large cosmological hydrodynamical simulations aimed at modelling the intergalactic medium (IGM) during and after the cosmic reionization of hydrogen. The suite consists of over 200 simulation... Read More about The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium.

Probing quasar lifetimes with proximate 21-centimetre absorption in the diffuse intergalactic medium at redshifts z ≥ 6 (2022)
Journal Article

Enhanced ionizing radiation in close proximity to redshift z ≳ 6 quasars creates short windows of intergalactic Ly α transmission blueward of the quasar Ly α emission lines. The majority of these Ly α near-zones are consistent with quasars that have... Read More about Probing quasar lifetimes with proximate 21-centimetre absorption in the diffuse intergalactic medium at redshifts z ≥ 6.

Comparison of Low-Redshift Lyman- α Forest Observations to Hydrodynamical Simulations with Dark Photon Dark Matter (2022)
Journal Article

Recent work has suggested that an additional ≲6.9 eV per baryon of heating in the intergalactic medium is needed to reconcile hydrodynamical simulations with Lyman-α forest absorption line widths at redshift z≃0.1. Resonant conversion of dark photon... Read More about Comparison of Low-Redshift Lyman- α Forest Observations to Hydrodynamical Simulations with Dark Photon Dark Matter.

Limits on non-canonical heating and turbulence in the intergalactic medium from the low redshift Lyman α forest (2022)
Journal Article

We examine the column density distribution function (CDDF) and Doppler parameter distribution from hydrodynamical simulations and Cosmic Origins Spectrograph (COS) observations of the Ly α forest at redshift 0 ≤ z ≤ 0.2. Allowing for a factor of two... Read More about Limits on non-canonical heating and turbulence in the intergalactic medium from the low redshift Lyman α forest.

The effect of inhomogeneous reionization on the Lyman α forest power spectrum at redshift z > 4: implications for thermal parameter recovery (2021)
Journal Article

We use the Sherwood–Relics suite of hybrid hydrodynamical and radiative transfer simulations to model the effect of inhomogeneous reionization on the 1D power spectrum of the Lyman α (Lyα) forest transmitted flux at redshifts 4.2 ≤ z ≤ 5. Relative to... Read More about The effect of inhomogeneous reionization on the Lyman α forest power spectrum at redshift z > 4: implications for thermal parameter recovery.

The effect of inhomogeneous reionisation on the Lyman-alpha forest power spectrum at redshift z > 4: implications for thermal parameter recovery (2021)
Journal Article

We use the Sherwood–Relics suite of hybrid hydrodynamical and radiative transfer simulations to model the effect of inhomogeneous reionization on the 1D power spectrum of the Lyman α (Lyα) forest transmitted flux at redshifts 4.2 ≤ z ≤ 5. Relative to... Read More about The effect of inhomogeneous reionisation on the Lyman-alpha forest power spectrum at redshift z > 4: implications for thermal parameter recovery.

The mean free path of ionizing photons at 5 &lt; z &lt; 6: evidence for rapid evolution near reionization (2021)
Journal Article

The mean free path of ionizing photons, λmfp, is a key factor in the photoionization of the intergalactic medium (IGM). At z ≳ 5, however, λmfp may be short enough that measurements towards QSOs are biased by the QSO proximity effect. We present new... Read More about The mean free path of ionizing photons at 5 &lt; z &lt; 6: evidence for rapid evolution near reionization.

Searching for the shadows of giants II: the effect of local ionisation on the Lyman-alpha absorption signatures of protoclusters at redshift z=2.4 (2021)
Journal Article

Local variations in the intergalactic medium (IGM) neutral hydrogen fraction will affect the Ly α absorption signature of protoclusters identified in tomographic surveys. Using the IllustrisTNG simulations, we investigate how the AGN proximity effect... Read More about Searching for the shadows of giants II: the effect of local ionisation on the Lyman-alpha absorption signatures of protoclusters at redshift z=2.4.

The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models (2021)
Journal Article

A late end to reionization at redshift z 5.3 is consistent with observed spatial variations in the Ly α forest transmission and the deficit of Ly α emitting galaxies around extended Ly α absorption troughs at z = 5.5. In this model, large islands of... Read More about The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models.

The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models (2021)
Journal Article

A late end to reionization at redshift z ≈ 5.3 is consistent with observed spatial variations in the Ly α forest transmission and the deficit of Ly α emitting galaxies around extended Ly α absorption troughs at z = 5.5. In this model, large islands o... Read More about The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models.

The evolution of the low-density H i intergalactic medium from z = 3.6 to 0: Data, transmitted flux, and H i column density (2020)
Journal Article

We present a new, uniform analysis of the H I transmitted flux (F) and H I column density (?NHI?) distribution in the low-density IGM as a function of redshift z for 0 < z < 3.6 using 55 HST/COS FUV (?z = 7.2 at z < 0.5), five HST/STIS+COS NUV (?z =... Read More about The evolution of the low-density H i intergalactic medium from z = 3.6 to 0: Data, transmitted flux, and H i column density.

Probing the thermal state of the intergalactic medium at z > 5 with the transmission spikes in high-resolution Ly?forest spectra (2020)
Journal Article

Searching for the shadows of giants: characterizing protoclusters with line of sight Lyman-α absorption (2019)
Journal Article

© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. We use state-of-the-art hydrodyamical simulations from the Sherwood, EAGLE, and Illustris projects to examine the signature of Mz = 0 ≃ 1014 M prot... Read More about Searching for the shadows of giants: characterizing protoclusters with line of sight Lyman-α absorption.

Revealing reionization with the thermal history of the intergalactic medium: new constrainst from the Lyα flux power spectrum (2019)
Journal Article

We present a new investigation of the thermal history of the intergalactic medium (IGM) during and after reionization using the Lyman-α forest flux power spectrum at 4.0 z 5.2. Using a sample of 15 high– resolution spectra, we measure the flux power... Read More about Revealing reionization with the thermal history of the intergalactic medium: new constrainst from the Lyα flux power spectrum.

A new measurement of the intergalactic temperature at z∼2.55 − 2.95 (2017)
Journal Article

We present two measurements of the temperature-density relationship (TDR) of the intergalactic medium (IGM) in the redshift range 2.55 < z < 2.95 using a sample of 13 high-quality quasar spectra and high resolution numerical simulations of the IGM. O... Read More about A new measurement of the intergalactic temperature at z∼2.55 − 2.95.