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Related papers: Observational constraints on Cosmic Reionization

200 papers

The reionisation of the intergalactic medium (IGM) was driven by the first stars, galaxies, and accreting black holes. However, the relative importance of these sources and the efficiency by which ionising photons escape into the IGM remain…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Timo P. Schwandt , Ivelin Georgiev , Sambit K. Giri , Garrelt Mellema , Ilian T. Iliev

The reionization of helium is thought to occur at $2.5\lesssim z\lesssim4$, marking the last phase transition and final global heating event of the intergalactic medium (IGM). Since it is driven by rare quasars, helium reionization should…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-13 Saba Etezad-Razavi , Sarah E. I. Bosman , Frederick B. Davies

During the EoR, the first stars and galaxies appear while creating ionized bubbles that will eventually percolate near z=6. These ionized bubbles and percolation process are nowadays under a lot of scrutiny since observations of the HI gas…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 Emilie Thélie , Dominique Aubert , Nicolas Gillet , Pierre Ocvirk

Reionization is thought to be dominated by low mass galaxies, while direct observations of resolved galaxies probe only the most massive, rarest objects. The cross-correlation between fluctuations in the surface brightness of the cumulative…

Astrophysics · Physics 2019-08-19 Stuart Wyithe , Avi Loeb , Brian Schmidt

We use numerical simulations of hydrogen reionization by stellar sources in the context of LCDM cosmogonies to investigate the 21 (1+z) cm radio signal expected from the diffuse intergalactic medium (IGM) prior to the epoch of reionization…

Astrophysics · Physics 2009-07-09 B. Ciardi , P. Madau

The GMRT reionization effort aims to map out the large scale structure of the Universe during the epoch of reionization (EoR). Removal of polarized Galactic emission is a difficult part of any 21 cm EoR program, and we present new upper…

The reionization of hydrogen in the intergalactic medium (IGM) is a crucial landmark in the history of the universe, but the processes through which it occurs remain mysterious. In particular, recent numerical and analytic work suggest that…

Astrophysics · Physics 2009-11-10 Steven Furlanetto , Lars Hernquist , Matias Zaldarriaga

The reionization of cosmic hydrogen marks a critical juncture in the history of structure formation in the universe. Here we present a new formulation of the standard reionization equation for the evolution of the volume-averaged HII…

Astrophysics of Galaxies · Physics 2017-12-13 Piero Madau

We study the observability of the reionization epoch through the 21 cm hyperfine transition of neutral hydrogen. We use a high-resolution cosmological simulation (including hydrodynamics) together with a fast radiative transfer algorithm to…

Astrophysics · Physics 2009-11-07 Steven Furlanetto , Aaron Sokasian , Lars Hernquist

We present new measurements of the intensity of the ionizing ultraviolet background and the global emissivity of ionizing photons over 2 < z < 5. Our results are based on a suite of updated measurements of physical properties of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 George D. Becker , James S. Bolton

Detections and non-detections of Lyman alpha (Ly$\alpha$) emission from $z>6$ galaxies ($<1$ Gyr after the Big Bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuring reionization's mid-stages, but…

We present new constraints on the 21cm Epoch of Reionization (EoR) power spectrum derived from 3 months of observing with a 32-antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of…

The local intensity of the 21 cm signal emitted during the Epoch of Reionization that will be mapped by the SKA is modulated by the amount of neutral hydrogen. Consequently, understanding the process of reionization of the intergalactic…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-20 Benoit Semelin , Ilian Iliev

Redshifted 21cm-line signal from neutral hydrogens in the intergalactic medium (IGM) gives a direct probe of the epoch of reionization (EoR). In this paper, we investigate the potential of the variance and skewness of the probability…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-31 Kenji Kubota , Shintaro Yoshiura , Hayato Shimabukuro , Keitaro Takahashi

We discuss expectations for the absorption of high-energy gamma-rays by gamma-gamma pair production with intergalactic radiation fields (IRFs) at very high redshifts (z~5-20), and the prospects thereof for probing the cosmic reionization…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Susumu Inoue , Ruben Salvaterra , Tirthankar Roy Choudhury , Andrea Ferrara , Benedetta Ciardi , Raffaella Schneider

We study the evolution of the ionization state of the IGM at the end of the reionization epoch using spectra of a sample of nineteen quasars at 5.74<z<6.42 discovered in the SDSS. Three methods are used to trace IGM properties: (a) the…

The Epoch of Reionization (EoR) is a key period of cosmological history in which the intergalactic medium (IGM) underwent a major phase change from being neutral to almost completely ionized. Gamma-ray bursts (GRBs) are luminous and unique…

We study the reionization history of the Universe in cosmological models with non-Gaussian density fluctuations, taking them to have a renormalized $\chi^2$ probability distribution function parametrized by the number of degrees of freedom,…

Astrophysics · Physics 2009-11-11 Pedro P. Avelino , Andrew R. Liddle

Observations of the 21 cm line from neutral hydrogen indicate that an Epoch of Heating (EoH) might have preceded the later Epoch of Reionization (EoR). Here we study the effects on the ionization state and the thermal history of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-26 Marius Berge Eide , Luca Graziani , Benedetta Ciardi , Yu Feng , Koki Kakiichi , Tiziana di Matteo

Measurements of the intergalactic medium (IGM) temperature provide a potentially powerful constraint on the reionisation history due to the thermal imprint left by the photo-ionisation of neutral hydrogen. However, until recently IGM…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Sudhir Raskutti , James S. Bolton , J. Stuart B. Wyithe , George D. Becker