Related papers: Modelling recombinations during cosmological reion…
We discuss the role of recombinations in the IGM, and the related concept of the clumping factor, during cosmic reionization. The clumping factor is, in general, a local quantity that depends on the local over-density and the scale below…
The recombination clumping factor, $C$, is a key parameter in modeling cosmic reionization, but its value is sensitive to the definition of the Intergalactic Medium (IGM). We investigate the clumping factor using the GAMER adaptive mesh…
We use fully self-consistent numerical simulations of cosmic reionization, completed under the Cosmic Reionization On Computers (CROC) project, to explore how well the recombinations in the ionized IGM can be quantified by the effective…
Cosmic reionization was driven by the imbalance between early sources and sinks of ionizing radiation, both of which were dominated by small-scale structure and are thus usually treated in cosmological reionization simulations by subgrid…
By depleting the ionizing photon budget available to expand cosmic HII regions, recombining systems (or Lyman limit systems) can have a large impact during (and following) cosmic reionization. Unfortunately, directly resolving such…
Estimating the intergalactic medium ionization level of a region needs proper treatment of the reionization process for a large representative volume of the universe. The clumping factor, a parameter which accounts for the effect of…
The history of reionization reflects the cumulative injection of ionizing photons by sources and the absorption of ionizing photons by sinks. The latter process is traditionally described in terms of a "clumping factor" which encodes the…
We use a suite of cosmological hydrodynamic simulations including a self-consistent treatment for inhomogeneous reionisation to study the impact of galactic outflows and photoionisation heating on the volume-averaged recombination rate of…
The major theoretical limitation for extracting cosmological parameters from the CMB sky lies in the precision with which we can calculate the cosmological recombination process. Uncertainty in the details of hydrogen and helium…
The critical star formation rate density required to keep the intergalactic hydrogen ionised depends crucially on the average rate of recombinations in the intergalactic medium (IGM). This rate is proportional to the clumping factor C =…
An ionization front (I-front) that propagates through an inhomogeneous medium is slowed down by self-shielding and recombinations. We perform cosmological radiation hydrodynamics simulations of the I-front propagation during the epoch of…
The intergalactic medium is expected to clump on scales down to $10^4-10^8$ M$_{\odot}$ before the onset of reionization. The impact of these small-scale structures on reionization is poorly understood despite the modern understanding that…
Reionization is inhomogeneous for two reasons: the clumpiness of the intergalactic medium (IGM) and clustering of the discrete ionizing sources. While numerical simulations can in principle take both into account, they are at present…
Small-scale density fluctuations can significantly affect reionization but are typically modelled quite crudely. Unresolved fluctuations in numerical simulations and analytical calculations are included using a gas clumping factor,…
In this first of several application papers, we investigate the mechanics of reionization from stellar sources in high-z galaxies, the utility of various clumping factors on estimating the recombination time in the IGM, and the photon…
The critical star formation rate density required to keep the intergalactic hydrogen ionised depends crucially on the average rate of recombinations in the intergalactic medium (IGM). This rate is proportional to the clumping factor C =…
With the recent measurement of full sky cosmic microwave background polarization from WMAP, key cosmological degeneracies have been broken, allowing tighter constraints to be placed on cosmological parameters inferred assuming a standard…
We discuss constraints on cosmic reionisation and their implications on a cosmic SFR density $\rho_\mathrm{SFR}$ model; we study the influence of key-parameters such as the clumping factor of ionised hydrogen in the intergalactic medium…
We place new constraints on sources of ionizing and resonance radiation at the epoch of the recombination process using the recent CMB temperature and polarization spectra coming from WMAP. We find that non-standard recombination scenarios…
The density contrast of the Universe, parametrized in terms of the matter power spectrum and its variance, can amplify the signal of the free-free process in the plasma. The damping of fluctuations on scales smaller than the DM particle…