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Related papers: Cosmic Reionization and Galaxy Formation

200 papers

Reionization represents an important phase in the history of our Universe when ultraviolet radiation from the first luminous sources, primarily stars and accreting black holes, ionized the neutral hydrogen atoms in the intergalactic medium…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-18 Anirban Chakraborty , Tirthankar Roy Choudhury

Constraints on the ionization structure of the Intergalactic Medium are derived as directly imposed by observations in conjunction with the results of numerical simulations for structure formation. Under the assumption that the population…

Astrophysics · Physics 2009-11-10 A. Meiksin

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

We present a self-consistent, semi-analytical LCDM model of star formation and reionization. For the cosmological parameters favored by the WMAP data, our models consistently reproduce the optical depth to reionization, redshift of…

Astrophysics · Physics 2008-11-26 Saumyadip Samui , Raghunathan Srianand , Kandaswamy Subramanian

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Sourav Mitra , T. Roy Choudhury , Andrea Ferrara

The relation between high redshift galaxies and QSO absorption systems is discussed in the context of hierarchical galaxy formation. It is demonstrated that imprints of the reionization history of the universe are detectable in the…

Astrophysics · Physics 2007-05-23 Matthias Steinmetz

We study the morphologies and sizes of galaxies at z>5 using high-resolution cosmological zoom-in simulations from the Feedback In Realistic Environments project. The galaxies show a variety of morphologies, from compact to clumpy to…

Known populations of QSOs appear to fall short of producing the ionizing flux required for re-ionizing the universe. The alternative, galaxies as sources of ionizing photons, suffers from the problem that known types of galaxies are almost…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Michael Rauch

An ionization front (I-front) that propagates through an inhomogeneous medium is slowed down by self-shielding and recombinations. We perform cosmological radiation hydrodynamics simulations of the I-front propagation during the epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-12 Tsang Keung Chan , Alejandro Benitez-Llambay , Tom Theuns , Carlos Frenk , Richard Bower

We study the properties of self-shielding intergalactic absorption systems and their implications for the ionizing background. We find that cosmological simulations post-processed with detailed radiative transfer calculations generally are…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-14 Matthew McQuinn , S. Peng Oh , C. -A. Faucher-Giguere

The reionization epoch concludes when ionizing photons reach every corner of the Universe. Reionization has generally been assumed to be limited primarily by the rate at which galaxies produce ionizing photons, but the recent measurement of…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-22 Frederick B. Davies , Sarah E. I. Bosman , Steven R. Furlanetto , George D. Becker , Anson D'Aloisio

We present improved synthesis models of the evolving spectrum of the UV/X-ray diffuse background, updating and extending our previous results. A "minimal cosmic reionization model" is presented in which the galaxy UV emissivity traces…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-29 Francesco Haardt , Piero Madau

Using cosmological simulations that incorporate gas dynamics and gravitational forces, we investigate the influence of photoionization by a UV radiation background on the formation of galaxies. In our highest resolution simulations, we find…

Astrophysics · Physics 2009-10-28 David H. Weinberg , Lars Hernquist , Neal Katz

One of the key open questions in Cosmology is the nature of the sources that completed the cosmological hydrogen Reionization at z~5.2. High-z primeval galaxies have been long considered the main drivers for Reionization, with a minor role…

High-redshift QSO spectra show large spatial fluctuations in the Ly-alpha opacity of the intergalactic medium on surprisingly large scales at z>~5.5. We present a radiative transfer simulation of cosmic reionization driven by galaxies that…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Girish Kulkarni , Laura C. Keating , Martin G. Haehnelt , Sarah E. I. Bosman , Ewald Puchwein , Jonathan Chardin , Dominique Aubert

Constraining when and how reionisation began is pivotal for understanding when the first galaxies formed. Lyman-alpha (Ly$\alpha$) emission from galaxies is currently our most promising probe of these early stages. At z>7 the majority of…

Astrophysics of Galaxies · Physics 2023-04-25 Ting-Yi Lu , Charlotte Mason , Anne Hutter , Andrei Mesinger , Yuxiang Qin , Daniel P. Stark , Ryan Endsley

A possible explanation of the present discrepancy between the abundance of galactic subhaloes predicted by N-Body simulations with those observed in the Local Group is presented. We study the impact of an early reionization on the baryonic…

Astrophysics · Physics 2007-05-23 Andrea V. Maccio' , Ben Moore , Joachim Stadel , Doug Potter

Observations of high-z galaxies and gamma-ray bursts now allow for empirical studies during reionization. However, even deep surveys see only the brightest galaxies at any epoch and must extrapolate to arbitrary lower limits to estimate the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-09 Matthew D. Kistler , Hasan Yuksel , Andrew M. Hopkins

Early JWST observations have revealed substantial numbers of galaxies out to redshifts as high as $z \simeq 14$, reflecting a slow evolution of the galaxy UV luminosity function (LF) not anticipated by many models of galaxy evolution. The…

Astrophysics of Galaxies · Physics 2025-04-16 C. T. Donnan , J. S. Dunlop , R. J. McLure , D. J. McLeod , F. Cullen

We study the reionization of the Universe due to haloes that host galaxies undergoing bursts of star formation. By comparing the recent results from the James Webb Space Telescope (JWST) with the cosmological hydrodynamical simulation EAGLE…

Astrophysics of Galaxies · Physics 2026-05-06 Nachiket Joshi , Mahavir Sharma