Related papers: Spatial fluctuations of the intergalactic temperat…
Observations of the intergalactic medium (IGM) suggest that quasars reionize HeII in the IGM at z ~ 3. We have run a set of 190 and 430 comoving Mpc simulations of HeII being reionized by quasars to develop an understanding of the nature of…
The reionization of the second electron of helium shapes the physical state of intergalactic gas at redshifts between 2 < z < 5. Because performing full in situ radiative transfer in hydrodynamic simulations is computationally expensive for…
Understanding the sources responsible for reionizing the Universe is a key goal of observational cosmology. A discrepancy has existed between the metagalactic hydrogen ionization rate, Gamma_HI, predicted by early hydrodynamical simulations…
We calibrate here cosmological radiative transfer simulation with ATON/RAMSES with a range of measurements of the Lyman alpha opacity from QSO absorption spectra. We find the Lyman alpha opacity to be very sensitive to the exact timing of…
We compare a sample of five high-resolution, high S/N Ly$\alpha$ forest spectra of bright $6<z \lesssim 6.5$ QSOs aimed at spectrally resolving the last remaining transmission spikes at $z>5$ with those obtained from mock absorption spectra…
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…
The intergalactic medium (IGM) prior to the epoch of reionization consists mostly of neutral hydrogen gas. Ly-alpha photons produced by early stars resonantly scatter off hydrogen atoms, causing energy exchange between the radiation field…
Recently, there has been a great deal of interest in understanding the reionization of hydrogen in the intergalactic medium (IGM). One of the major outstanding questions is how this event proceeds on large scales. Motivated by numerical…
The spatial correlation between galaxies and the Ly$\alpha$ forest provides insights into how galaxies reionized the Universe. Here, we present initial results on the spatial cross-correlation between [OIII] emitters and Ly$\alpha$ forest…
We use a set of cosmological simulations combined with radiative transfer calculations to investigate the distribution of neutral hydrogen in the post-reionization Universe. We assess the contributions from the metagalactic ionizing…
We use a set of AMR hydrodynamic simulations post-processed with the radiative-transfer code RADAMESH to study how inhomogeneous HeII reionization affects the intergalactic medium (IGM). We propagate radiation from active galactic nuclei…
Numerical simulations indicate that the smooth, photoionized intergalactic medium (IGM) responsible for the low column density Lyman-alpha forest follows a well defined temperature-density relation. We show that such an equation of state…
The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of galaxy formation in gravitational models of…
It appears inevitable that reionization processes would have produced large-scale temperature fluctuations in the intergalactic medium. Using toy temperature models and detailed heating histories from cosmological simulations of HeII…
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…
TeV-blazars potentially heat the intergalactic medium (IGM) as their gamma rays interact with photons of the extragalactic background light to produce electron-positron pairs, which lose their kinetic energy to the surrounding medium…
We present the first simulations of the high-redshift Ly$\alpha$ intensity field that account for scattering in the intergalactic medium (IGM). Using a 3D Monte Carlo radiative transfer code, we find that Ly$\alpha$ scattering smooths…
Many models of early structure formation predict a period of heating immediately preceding reionization, when X-rays raise the gas temperature above that of the cosmic microwave background. These X-rays are often assumed to heat the…
We perform the first measurement of the thermal and ionization state of the intergalactic medium (IGM) across 0.9 < z < 1.5 using 301 \lya absorption lines fitted from 12 HST STIS quasar spectra, with a total pathlength of \Delta z=2.1. We…
The thermal history of the intergalactic medium (IGM) after reionization is to a large extent determined by photoheating. Here we demonstrate that calculations of the photoheating rate which neglect radiative transfer effects substantially…