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We compute the reionization histories of hydrogen and helium due to the ionizing radiation fields produced by stars and quasars. For the quasars we use a model based on halo-merger rates that reproduces all known properties of the quasar…

Astrophysics · Physics 2008-11-26 Stuart Wyithe , Abraham Loeb

Observations of the Epoch of Reionization (EoR) have the potential to answer long-standing questions of astrophysical interest regarding the nature of the first luminous sources and their effects on the intergalactic medium (IGM). We…

We show that various milestones of high-redshift galaxy formation, such as the formation of the first stars or the complete reionization of the intergalactic medium, occurred at different times in different regions of the universe. The…

Astrophysics · Physics 2012-01-06 Rennan Barkana , Abraham Loeb

We analyze the limits on resonant particle production during inflation based upon the power spectrum of fluctuations in matter and the cosmic microwave background. We show that such a model is consistent with features observed in the matter…

Astrophysics · Physics 2009-11-10 G. J. Mathews , D. J. H. Chung , K. Ichiki , T. Kajino , M. Orito

We use cosmological simulations to explore the large-scale effects of reionization. Since reionization is a process that involves a large dynamic range - from galaxies to rare bright quasars - we need to be able to cover a significant…

Astrophysics · Physics 2008-11-26 Katharina Kohler , Nickolay Y. Gnedin , Andrew J. S. Hamilton

The 21-cm signal from the epoch of reionization is non-Gaussian. Current radio telescopes are focused on detecting the 21-cm power spectrum, but in the future the Square Kilometre Array is anticipated to provide a first measurement of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Sambit K. Giri , Anson D'Aloisio , Garrelt Mellema , Eiichiro Komatsu , Raghunath Ghara , Suman Majumdar

We study the viability of using power spectrum clustering wedges as summary statistics of 21cm surveys during the Epoch of Reionization (EoR). For observations in a wide redshift range $z\sim 7-9$ corresponding to a line-of-sight scale of…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-31 Zhaoting Chen , Alkistis Pourtsidou

The measurements of the 21-cm brightness temperature fluctuations from the neutral hydrogen at the Epoch of Reionization (EoR) should inaugurate the next generation of cosmological observables. In this respect, many works have concentrated…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-10 Sebastien Clesse , Laura Lopez-Honorez , Christophe Ringeval , Hiroyuki Tashiro , Michel H. G. Tytgat

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-29 Adélie Gorce , Marian Douspis , Nabila Aghanim , Mathieu Langer

Cosmic reionization is driven by the formation of sources of ultraviolet photons, and hence it is an intrinsically asymmetric process, where its earlier stages occur at a slower pace relative to its later stages. Yet most modern cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-16 Paulo Montero-Camacho , Yin Li , Marco Barquero-Hernández , Pablo Renard , Yang Wang , Xiao-Dong Li

We highlight recent progress in the sophistication and diversification of cosmic dawn and reionization simulations. The application of these modeling tools to current observations has allowed us narrow down the timing of reionization, which…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 Andrei Mesinger

We examine the constraints on the epoch of reionization (redshift z_r) set by recent WMAP-3 observations of tau_e = 0.09 +/- 0.03, the electron-scattering optical depth of the cosmic microwave background (CMB), combined with models of…

Astrophysics · Physics 2007-05-23 Michael Shull , Aparna Venkatesan

The feasibility of making highly redshifted HI 21-cm (rest frame) measurements from an early epoch of the Universe between the Dark Ages and Reionization (i.e., z>6 and nu<200 MHz) to probe the effects of feedback from the first stars and…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-15 Jack O. Burns

This paper focuses on cosmological constraints derived from analysis of WMAP data alone. A simple LCDM cosmological model fits the five-year WMAP temperature and polarization data. The basic parameters of the model are consistent with the…

Exploiting a fundamental characteristic of galaxy assembly in the {\Lambda}CDM paradigm, the observed spatial biasing and kinematics of metal-poor globular star clusters are used to constrain the local reionization epoch around individual…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Lee R. Spitler , Aaron J. Romanowsky , Jürg Diemand , Jay Strader , Duncan A. Forbes , Ben Moore , Jean P. Brodie

The redshift at which the universe was reionized is currently unknown. We examine the optimal strategy for extracting this redshift, z_{reion}, from the spectra of early sources. For a source located at a redshift z_s beyond but close to…

Astrophysics · Physics 2009-10-30 Zoltan Haiman , Abraham Loeb

We derive constraints on the thermal and ionization states of the intergalactic medium (IGM) at redshift $\approx$ 9.1 using new upper limits on the 21-cm power spectrum measured by the LOFAR radio-telescope and a prior on the ionized…

Improvements in current instruments and the advent of next-generation instruments will soon push observational 21 cm cosmology into a new era, with high significance measurements of both the power spectrum and the mean ("global") signal of…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-08 Adrian Liu , Aaron R. Parsons

The global history of reionization was shaped by the relative amounts of starlight released by three halo mass groups: atomic-cooling halos (ACHs) with virial temperatures Tvir > 10^4 K, either (1) massive enough to form stars even after…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Kyungjin Ahn , Paul R. Shapiro

The observational tests for the period of reionization of the universe are discussed. We show that this period can be observed as {\it negative} intensity patches of the CMB radiation with the amplitude $\delta T/T\sim 10^{-5}$ and the…

Astrophysics · Physics 2009-11-07 A. Doroshkevich , V. Dubrovich
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