Related papers: Probing Helium Reionization Through the $^{3}\math…
Recent observations suggest that hydrogen reionization ends late ($z \simeq 6$) and proceeds quickly. We present here a new model of the meta-galactic UV/X-ray background (UVB) that is consistent with this. It adopts the most recent…
We introduce a new project to understand helium reionization using fully coupled $N$-body, hydrodynamics, and radiative transfer simulations. This project aims to capture correctly the thermal history of the intergalactic medium (IGM) as a…
We estimate the global signal in the redshifted hyperfine structure line 21 cm of hydrogen atoms formed during the Dark Ages and Cosmic Dawn epochs. The evolution of the brightness temperature in this line was computed to study its…
The redshifted 21-cm signal from the epoch of reionization (EoR) directly probes the ionization and thermal states of the intergalactic medium during that period. In particular, the distribution of the ionized regions around the radiating…
We analyze the formation of the redshifted hyperfine structure line 21-cm of hydrogen atom in the Dark Ages, Cosmic Dawn, and Reionization epochs. The evolution of the global differential brightness temperature in this line was computed to…
We constrain the H I photoionization rate $(\Gamma_{\rm HI})$ at $z \lesssim 0.45$ by comparing the flux probability distribution function and power spectrum of the Ly-$\alpha$ forest data along 82 QSO sightlines obtained using Cosmic…
We analyze the formation of the signal in the 21 cm hydrogen line of the Dark Ages ($30\le z\le300$) in different cosmological models and discuss the possibility of its detection by decameter-wavelength radio telescopes. To study the…
We present results from a large volume simulation of Hydrogen reionization. We combine 3d radiative transfer calculations and an N-body simulation, describing structure formation in the intergalactic medium, to detail the growth of HII…
We assess the impact of inhomogeneous reionization on detection of HII regions surrounding luminous high redshift quasars using planned low frequency radio telescopes. Our approach is to implement a semi-numerical scheme to calculate the…
The post-recombination streaming of baryons through dark matter keeps baryons out of low mass (<10^6 solar masses) halos coherently on scales of a few comoving Mpc. It has been argued that this will have a large impact on the 21-cm signal…
We implement a treatment of Helium {\sc ii} absorption and re-emission into the \TD cosmological simulations to study its impact on the metagalactic ultraviolet background (UVB) in three dimensions. By comparing simulations with and without…
Interpretation of He II Ly{\alpha} absorption spectra after the epoch of He II reionization requires knowledge of the He II ionizing background. While past work has modelled the evolution of the average background, the standard cosmological…
The emission from neutral hydrogen (HI) clouds in the post-reionization era (z < 6), too faint to be individually detected, is present as a diffuse background in all low frequency radio observations below 1420 MHz. The angular and frequency…
Intergalactic medium temperature is a powerful probe of the epoch of reionisation, as information is retained long after reionisation itself. However, mean temperatures are highly degenerate with the timing of reionisation, with the amount…
The introduction of low-frequency radio arrays is expected to revolutionize the study of the reionization epoch. Observation of the contrast in redshifted 21cm emission between a large HII region and the surrounding neutral inter-galactic…
We study the statistical properties of the cosmological 21 cm signal from both the intergalactic medium (IGM) and minihalos, using a reionization simulation that includes a self--consistent treatment of minihalo photoevaporation. We…
We present a new suite of late-end reionization simulations performed with ATON-HE, a revised version of the GPU-based radiative transfer code ATON that includes helium. The simulations are able to reproduce the Ly$\alpha$ flux distribution…
The neutral hydrogen (HI) power spectrum, measured from intensity fluctuations in the 21-cm background, offers insights into the large-scale structures (LSS) of our Universe in the post-reionization era (redshift $z<6$). A significant…
The low density hydrogen and helium in the IGM probed by QSO absorption lines is sensitive to the amplitude and spectral shape of the metagalactic UV background. We use realistic HI and HeII Ly-alpha forest spectra, constructed from…
The epoch of reionization (EoR) marks the last phase transition of hydrogen in our Universe, as it evolves from cold and neutral to hot and ionized in the intergalactic medium (IGM). While its endpoint and duration can be estimated from…