Related papers: Heating of the Intergalactic Medium by Hydrogen Re…
Ionization balance in the intergalactic medium (IGM) is central to the interpretation of quasar absorption spectra, linking observed ionic columns to the underlying gas density, temperature, metallicity, and ionizing radiation field.…
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 compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a…
In situ observations of the solar wind frequently show the temperature of $\alpha$-particles (fully ionized helium), $T_\alpha$, to significantly differ from that of protons (ionized hydrogen), $T_p$. Many heating processes in the plasma…
I explore the thermal evolution and ionization states in gas cooling from an initially hot state in the presence of external photoionizing radiation. I compute the equilibrium and nonequilibrium cooling efficiencies, heating rates, and ion…
Cosmic rays (CRs) govern the energetics of present-day galaxies and might have also played a pivotal role during the Epoch of Reionization. In particular, energy deposition by low-energy ($E \lesssim 10$ MeV) CRs accelerated by the first…
We develop a numerical solver for radiative transfer problems based on the weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive flux corrections, in order to solve the temperature and ionization profiles around a…
In this paper we review the current predictions of numerical simulations for the origin and observability of the warm hot intergalactic medium (WHIM), the diffuse gas that contains up to 50 per cent of the baryons at z~0. During structure…
Reionization is a process whereby hydrogen (and helium) in the Universe is ionized by the radiation from first luminous sources. Theoretically, the importance of the reionization lies in its close coupling with the formation of first cosmic…
We simulate a plausible cosmological model in considerable physical and numerical detail through the successive phases of reheating (at 10<z<20), formation of Pop III stars at z=15 (due to molecular hydrogen cooling), with subsequent…
Early galaxies were the radiation source for reionization, with the photoheating feedback from the reionization process expected to reduce the efficiency of star formation in low mass haloes. Hence, to fully understand reionization and…
The effect of the primeval sources of radiation and particles on the thermodynamical state of the intergalactic medium during the Epoch of Reionisation is still unclear. In this work, we explore the contribution of electrons accelerated in…
Spatial variations of the [S II]/H-Alpha and [N II]/H-Alpha line intensity ratios observed in the gaseous halo of the Milky Way and other galaxies are inconsistent with pure photoionization models. They appear to require a supplemental…
The ionizing background determines the ionization balance and the thermodynamics of the cosmic gas. It is therefore a fundamental ingredient to theoretical and empirical studies of both the IGM and galaxy formation. We present here a new…
I present an overview of some of the recent advances in our understanding of the distribution and evolution of the ordinary, baryonic matter in the universe. Two observations that strongly suggest that most of the baryons seen at high…
In this paper we investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain the UV Luminosity Function in…
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 report the most sensitive upper limits to date on the 21 cm epoch of reionization power spectrum using 94 nights of observing with Phase I of the Hydrogen Epoch of Reionization Array (HERA). Using similar analysis techniques as in…
Radiative cooling by metals in shocked gas mediates the formation of ionization front instabilities in the galaxy today that are responsible for a variety of phenomena in the interstellar medium, from the morphologies of nebulae to…
Using high redshift radio sources as background, the 21cm forest observations probe the neutral hydrogen absorption signatures of early structures along the lines of sight. Directly sensitive to the spin temperature, it complements the 21cm…