相关论文: The Reionization Parameter Space Consistent with t…
A new parametrization of the reionization history is presented to facilitate robust comparisons between different observations and with theory. The evolution of the ionization fraction with redshift can be effectively captured by specifying…
We investigate constraints on cosmic reionization extracted from the Planck cosmic microwave background (CMB) data. We combine the Planck CMB anisotropy data in temperature with the low-multipole polarization data to fit LCDM models with…
We conduct an analysis of the Planck 2015 data that is complete in reionization observables from the large angle polarization $E$-mode spectrum in the redshift range $6 < z < 30$. Based on 5 principal components, all of which are…
The recent discovery of a high optical depth tau to Thomson scattering from the WMAP data implies that significant reionization took place at redshifts z~15. This discovery has important implications for the sources of reionization, and…
We perform an analysis of the cosmic reionization in the standard cold dark matter (CDM) paradigm and in alternative dark matter scenarios. Building upon the work of Corasaniti et al. (2017), we predict the reionization history for CDM, for…
Motivated by the current constraints on the epoch of reionisation from recent cosmic microwave background observations, ionising background measurements of star-forming galaxies, and low redshifts line-of-sight probes, we propose a new…
We constrain the history of reionization using the data from Planck 2015 Cosmic Microwave Background (CMB) temperature and polarization anisotropy observations. We also use prior constraints on the reionization history at redshifts…
Cosmic Microwave Background temperature and polarization anisotropies from Planck have estimated a lower value of the optical depth to reionization ($\tau$) compared to WMAP. A significant period in the reionization history would then fall…
Current data of high-redshift absorption-line systems imply that hydrogen reionization occurred before redshifts of about 5. Previous works on reionization by the first stars or quasars have shown that such scenarios are described by a…
The simple assumption of an instantaneous reionization of the Universe may bias estimates of cosmological parameters. In this paper a model-independent principal component method for the reionization history is applied to give constraints…
In light of the recent inference of a high optical depth to Thomson scattering, tau, from the WMAP data we investigate the effects of extended periods of partial ionization and ask if the value of tau inferred by assuming a single sharp…
The epoch of reionisation is a key phase in cosmic history, characterised by the ionisation of the intergalactic medium by the first luminous sources. In this work, we constrain the reionisation history of the Universe using data from the…
We study the constraints on reionization from five years of WMAP data, parametrizing the evolution of the average fraction of ionized hydrogen with principal components that provide a complete basis for describing the effects of…
We study the effect of a prolonged epoch of reionization on the angular power spectrum of the Cosmic Microwave Background. Typically reionization studies assume a sudden phase transition, with the intergalactic gas moving from a fully…
With a simple power-law approximation of high-redshift ($\gtrsim3.5$) star formation history, i.e., $\dot{\rho}_*(z)\propto [(1+z)/4.5]^{-\alpha}$, we investigate the reionization of intergalactic medium (IGM) and the consequent Thomson…
Cosmic reionization holds the key to understand structure formation in the Universe, and can inform us about the properties of the first sources, as their star formation efficiency and escape fraction of ionizing photons. By combining the…
The optical depth $\tau$ is the least well determined parameter in the standard model of cosmology, and one whose precise value is important for both understanding reionization and for inferring fundamental physics from cosmological…
We study the relationship between signatures of high redshift ionization in large-angle CMB polarization power spectra and features in the Planck 2015 data. Using a principal component (PC) ionization basis that is complete to the cosmic…
We present constraints on the reionization optical depth, $\tau$, obtained using several independent methods. First, we perform a non-parametric reconstruction of the reionization history, using Lyman-$\alpha$ constraints on the evolution…
We investigate the constraints on the reionization history of the Universe from a joint analysis of the cosmic microwave background and neutral hydrogen fraction data. The $\tanh$ parametrization and principal component analysis methods are…