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Related papers: Computer Simulations of Cosmic Reionization

200 papers

Galaxy simulations have come a long way from the early days of simple N-body calculations, which considered only gravitational interactions, to the complex, multi-physics models used today. Beginning with initial conditions representative…

Astrophysics of Galaxies · Physics 2025-07-15 Robert Feldmann , Rebekka Bieri

Cosmic rays are the main agents in controlling the chemical evolution and setting the ambipolar diffusion time of a molecular cloud. We summarise the processes causing the energy degradation of cosmic rays due to their interaction with…

Astrophysics of Galaxies · Physics 2014-06-11 Marco Padovani , Patrick Hennebelle , Daniele Galli

Recent observations on the cosmic microwave background by Wilkinson Microwave Anisotropy Probe(WMAP) strongly suggest that the reionization of the universe took place quite early (z \sim 17). On the other hand, it has been pointed out that…

Astrophysics · Physics 2009-11-10 Hajime Susa , Masayuki Umemura

Early galaxies were the radiation source for reionization, with the photoheating feedback from the reionization process expected to reduce the efficiency of star formation in low mass haloes. Hence, to fully understand reionization and…

The study of cosmic phase transitions are of central interest in modern cosmology. In the standard model of cosmology the Universe begins in a very hot state, right after at the end of inflation via the process of reheating/preheating, and…

High Energy Physics - Phenomenology · Physics 2019-12-20 Anupam Mazumdar , Graham White

The formation of the first stars and quasars marks the transformation of the universe from its smooth initial state to its clumpy current state. In popular cosmological models, the first sources of light began to form at redshift 30 and…

Astrophysics · Physics 2011-08-23 Rennan Barkana , Abraham Loeb

Although empirical evidence indicates that that the universe's gas had become ionized by redshift z ~ 6, the mechanism by which this transition occurred remains unclear. In this article, we explore the possibility that dark matter…

High Energy Physics - Phenomenology · Physics 2009-09-02 Alexander V. Belikov , Dan Hooper

Observational studies indicate that the intergalactic medium (IGM) is highly ionized up to redshifts just over 6. A number of models have been developed to describe the process of reionization and the effects of the ionizing photons from…

Astrophysics · Physics 2009-11-07 Aparna Venkatesan , Mark L. Giroux , J. Michael Shull

We compare the results from several sets of cosmological simulations of cosmic reionization, produced under Cosmic Reionization On Computers (CROC) project, with existing observational data on the high-redshift Ly-alpha forest and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Nickolay Y. Gnedin , Alexander A. Kaurov

We study the reionization scenario in which ionizing UV photons emitted from decaying particle, in addition to usual contributions from stars and quasars, ionize the universe. It is found that the scenario is consistent with both the first…

Astrophysics · Physics 2009-11-10 S. Kasuya , M. Kawasaki

We present a detailed analysis of the ionization and thermal structure of the intergalactic medium (IGM) around a high-redshift QSO using a large suite of cosmological, multi-frequency radiative transfer (RT) simulations, exploring the…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-18 Koki Kakiichi , Luca Graziani , Benedetta Ciardi , Avery Meiksin , Michele Compostella , Marius B. Eide , Saleem Zaroubi

Photoionization and its inverse, electron-ion recombination, are key processes that influence many astrophysical plasmas (and gasses), and the diagnostics that we use to analyse the plasmas. In this review we provide a brief overview of the…

Solar and Stellar Astrophysics · Physics 2023-03-21 D. John Hillier

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

Cosmic reionization is thought to be primarily fueled by the first generations of galaxies. We examine their stellar and gaseous properties, focusing on the star formation rates and the escape of ionizing photons, as a function of halo…

Astrophysics of Galaxies · Physics 2016-12-14 Hao Xu , John H. Wise , Michael L. Norman , Kyungjin Ahn , Brian W. O'Shea

I review recent progress and challenges in studies of the earliest galaxies, seen when the Universe was less than 1 billion years old. Can they be used as reliable tracers of the physics of cosmic reionization thereby complementing other,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-14 Richard S. Ellis

This paper reviews our current understanding of the process of re-ionization of the Universe, focusing especially on those models where re-ionization is caused by UV radiation from massive stars. After reviewing the expected properties of…

Astrophysics · Physics 2015-06-24 Massimo Stiavelli

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

In recent years there has been considerable progress in our understanding of the nature and properties of the reionization process. In particular, the numerical simulations of this epoch have made a qualitative leap forward, reaching…

We consider the early stages of cosmic hydrogen or helium reionization, when ionizing sources were still rare. We show that Poisson fluctuations in the galaxy distribution substantially affected the early bubble size distribution, although…

Astrophysics · Physics 2009-11-13 Rennan Barkana

The bulk of the hydrogen in the universe transformed from neutral to ionized somewhere in the redshift interval 5 < z < 40, most likely due to ionizing photons produced by an early generation of stars or mini-quasars. The resulting free…

Astrophysics · Physics 2007-05-23 Zoltan Haiman , Lloyd Knox