Related papers: Updating reionization scenarios after recent data
Recent observations show that the measured rates of star formation in the early universe are insufficient to produce re-ionization, and therefore, another source of ionizing photons is required. In this \emph{Letter}, we examine the…
We investigate the effects of a top-heavy stellar initial mass function on the reionisation history of the intergalactic medium (IGM). We use cosmological simulations that include self-consistently the feedback from ionising radiation, H_2…
Standard analyses of the reionization history of the universe from Planck cosmic microwave background (CMB) polarization measurements consider only the overall optical depth to electron scattering ($\tau$), and further assume a step-like…
We present a large sample of candidate galaxies at z~7--10, selected in the HUDF using the new observations made by the HST/WFC3. Our sample is composed of 20 z-dropouts, 15 Y-dropouts, and 20 J-dropouts. The surface densities of the…
Recent results by the WMAP satellite suggest that the intergalactic medium was significantly reionized at redshifts as high as z~17. At this early epoch, the first ionizing sources likely appeared in the shallow potential wells of…
The protagonists of cosmic reionization remain elusive. Faint star-forming galaxies are leading candidates because they are numerous and may have significant ionizing photon escape fractions ($f_{esc}$). Here we update this picture via an…
The Wilkinson Microwave Anisotropy Probe (WMAP) experiment has detected reionization at the $5.5 \sigma$ level and has reported a mean optical depth of $0.088 \pm 0.015$. A powerful probe of reionization is the large-angle $EE$ polarization…
We investigate the connection between the epoch of reionization and the present day universe, by examining the extended mass reionization histories of dark matter halos identified at z=0. We combine an N-body dark matter simulation of a 600…
We present a new hybrid code for large volume, high resolution simulations of cosmic reionization, which utilizes a N-body algorithm for dark matter, physically motivated prescriptions for baryons and star formation, and an adaptive ray…
I show that advanced simulations of cosmological reionization are able to fit the observed data on the mean transmitted flux in the hydrogen Lyman-alpha line at z~6. At the same time, posteriori models can be constructed that also produce a…
The first Pop III stars formed out of primordial, metal free gas, in minihalos at z>20, and kickstarted the cosmic processes of reionizaton and enrichment. While these stars are likely more massive than their enriched counterparts, the…
The high ionization level and universal metallicity (1% solar) of the intergalactic gas at redshifts z<5 implies that nonlinear structure had started to form in the universe at earlier times than we currently probe. In Cold Dark Matter…
Starlight from galaxies plays a pivotal role throughout the process of cosmic reionisation. We present the statistics of dwarf galaxy properties at z > 7 in haloes with masses up to 10^9 solar masses, using a cosmological radiation…
We assess a model of late cosmic reionization in which the ionizing background radiation arises entirely from high redshift quasars and other active galactic nuclei (AGNs). The low optical depth to Thomson scattering reported by the Planck…
We combine observational data on a dozen independent cosmic properties at high-$z$ with the information on reionization drawn from the spectra of distant luminous sources and the cosmic microwave background (CMB) to constrain the…
Recent JWST observations at $z > 6$ may imply galactic ionizing photon production above prior expectations. Under observationally motivated assumptions about escape fractions, these suggest a $z \sim 8-9$ end to reionization, in tension…
$\require{mediawiki-texvc}$Cosmic Reionisation commenced when ultraviolet (UV) radiation produced in the first galaxies began illuminating the cold, neutral gas that filled the primordial Universe. Recent James Webb Space Telescope (JWST)…
We present simulations of cosmic reionization and reheating from $z=18$ to $z=5$, investigating the role of stars (emitting soft UV-photons), nuclear black holes (BHs, with power-law spectra), X-ray binaries (XRBs, with hard X-ray dominated…
We implemented Population III (Pop. III) star formation in mini-halos within the MERAXES semi-analytic galaxy formation and reionisation model, run on top of a N-body simulation with $L = 10 h^{-1}$ cMpc with 2048$^3$ particles resolving…
Population III stars supplied the first light and metals in the Universe, setting the pace of re-ionisation and early chemical enrichment. In dense haloes their evolution can be strongly influenced by the energy released when WIMPs…