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Related papers: Cosmic reionization after Planck II: contribution …

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We provide an update on the constraints on extended reionization histories with the Planck 2018 cosmic microwave background anisotropy data. The Planck 2018 data on large angular scales improve the measurement of the $E$-mode polarization…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Daniela Paoletti , Dhiraj Kumar Hazra , Fabio Finelli , George F. Smoot

In this work, the sixth of a series, we use the ASTRAEUS (semi-numerical rAdiative tranSfer coupling of galaxy formaTion and Reionization in N-body dark matter simUlationS) framework to investigate the nature of the sources that reionized…

Astrophysics of Galaxies · Physics 2022-12-07 Maxime Trebitsch , Anne Hutter , Pratika Dayal , Stefan Gottlöber , Laurent Legrand , Gustavo Yepes

After the so-called cosmic recombination, the expanding universe entered into a period of darkness since most of the matter was in a neutral state. About a billion years later, however, the intergalactic space was once again ionized. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-15 Matias Tueros , Maria Victoria del Valle , Gustavo Esteban Romero

We present new upper limits on the volume-weighted neutral hydrogen fraction, <xHI>, at z~5-6 derived from spectroscopy of bright quasars. The fraction of the Lyman-alpha and Lyman-beta forests that is "dark" (with zero flux) provides the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Ian McGreer , Andrei Mesinger , Valentina D'Odorico

We investigate the effect of helium on hydrogen reionisation using a hydrodynamical simulation combined with the cosmological radiative transfer code CRASH. The simulations are run in a 35.12/h comoving Mpc box using a variety of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 B. Ciardi , J. S. Bolton , A. Maselli , L. Graziani

Recent deep surveys have unravelled a population of faint active galactic nuclei (AGN) in the high redshift Universe, leading to various discussions on their nature and their role during the Epoch of Reionization. We use cosmological…

Astrophysics of Galaxies · Physics 2020-04-29 Maxime Trebitsch , Marta Volonteri , Yohan Dubois

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Dhiraj Kumar Hazra , Daniela Paoletti , Fabio Finelli , George F. Smoot

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Wei-Ming Dai , Yin-Zhe Ma , Zong-Kuan Guo , Rong-Gen Cai

On large angular scales, CMB polarization depends mostly on the evolution of the ionization level of the IGM during reionization. In order to avoid biasing parameter estimates, an accurate and model independent approach to reionization is…

Astrophysics · Physics 2009-06-23 Loris P. L. Colombo , Elena Pierpaoli

The Epoch of Reionization (EoR) began when galaxies grew in abundance and luminosity, so their escaping Lyman continuum (LyC) radiation started ionizing the surrounding neutral intergalactic medium (IGM). Despite significant recent…

Dark matter annihilation or decay could have a significant impact on the ionisation and thermal history of the universe. In this paper, we study the potential contribution of dark matter annihilation (s-wave- or p-wave-dominated) or decay…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-14 Hongwan Liu , Tracy R. Slatyer , Jesús Zavala

(ABRIDGED)The rise of cosmic structure depends upon the statistical distribution of initial density fluctuations generated by inflation. While the simplest models predict an almost perfectly Gaussian distribution, more-general models…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Anson D'Aloisio , Jun Zhang , Paul R. Shapiro , Yi Mao

Observations of resolved HeII Lyman alpha absorption in spectra of two QSO's suggest that the epoch of helium ionization occurred at z~3. Proximity zones in the spectra of the quasars (z=3.18, 3.285) at 304 A resemble Stromgren spheres,…

Astrophysics · Physics 2009-10-31 James W. Wadsley , Craig J. Hogan , Scott F. Anderson

The high redshift Lyman-alpha forest, in particular the Gunn-Peterson trough, is the most unambiguous signature of the neutral to ionized transition of the intergalactic medium (IGM) taking place during the Epoch of Reionization (EoR).…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Pierre Ocvirk , Joseph S. W. Lewis , Nicolas Gillet , Jonathan Chardin , Dominique Aubert , Nicolas Deparis , Emilie Thelie

One still cannot conclusively assert that the universe underwent a neutral phase, despite the new COBE FIRAS limit y<0.000025 on Compton y-distortions of the cosmic microwave background. Although scenarios where the very early (z=1000)…

Astrophysics · Physics 2009-10-07 Max Tegmark , Joseph Silk

The origin of the ionizing photons that completed hydrogen reionization remains debated. Using recent JWST and ground-based surveys at 4.5 <= z <= 6.5, we construct a unified rest-UV AGN luminosity function that separates unobscured Type I…

Astrophysics of Galaxies · Physics 2025-11-03 Mainak Singha , Sangeeta Malhotra , James Ely Rhoads

Quasars at cosmic dawn provide powerful probes of the formation and growth of the earliest supermassive black holes (SMBHs) in the universe, their connections to galaxy and structure formation, and the evolution of the intergalactic medium…

Astrophysics of Galaxies · Physics 2022-12-15 Xiaohui Fan , Eduardo Banados , Robert A. Simcoe

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…

Astrophysics of Galaxies · Physics 2017-05-10 Piero Madau , Tassos Fragos

We investigate the implications of our measurement of the Lyman-alpha forest opacity at redshifts 2<z<4.2 from a sample of 86 high-resolution quasar spectra for the evolution of the cosmic ultraviolet luminosity density and its sources. The…

Astrophysics · Physics 2009-11-13 C. -A. Faucher-Giguere , A. Lidz , L. Hernquist , M. Zaldarriaga

Large-scale polarization of the cosmic microwave background measured by the WMAP satellite requires a mean optical depth to Thomson scattering, tau_e ~ 0.17. The reionization of the universe must therefore have begun at relatively high…

Astrophysics · Physics 2009-11-07 B. Ciardi , A. Ferrara , S. D. M. White