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Related papers: Simulating Reionization in Numerical Cosmology

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The recombination clumping factor, $C$, is a key parameter in modeling cosmic reionization, but its value is sensitive to the definition of the Intergalactic Medium (IGM). We investigate the clumping factor using the GAMER adaptive mesh…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Yuri Oku , Renyue Cen

Elucidating the processes that shape the circumgalactic medium (CGM) is crucial for understanding galaxy evolution. Absorption and emission diagnostics can be interpreted using photoionization calculations to obtain information about the…

Following the completion of cosmic reionization, the mean-free-path of ionizing photons was set by a population of Ly-limit absorbers. As the mean-free-path steadily grew, the intensity of the ionizing background also grew, thus lowering…

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

Radiative processes play a pivotal role in shaping the thermal and chemical states of gas across diverse astrophysical environments, from the interstellar medium (ISM) to the intergalactic medium. We present a hybrid cooling model for…

The amplitude of the ionizing background that pervades the intergalactic medium (IGM) at the end of the epoch of reionization provides a valuable constraint on the emissivity of the sources which reionized the Universe. While measurements…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Frederick B. Davies , Joseph F. Hennawi , Anna-Christina Eilers , Zarija Lukić

We introduce a new suite of radiation-hydrodynamical simulations of galaxy formation and reionization called Aurora. The Aurora simulations make use of a spatially adaptive radiative transfer technique that lets us accurately capture the…

Astrophysics of Galaxies · Physics 2017-01-18 Andreas H. Pawlik , Alireza Rahmati , Joop Schaye , Myoungwon Jeon , Claudio Dalla Vecchia

Aims: We systematically explore a plausible subset of the parameter space involving effective temperatures and metallicities of the ionizing stellar sources, the effects of the hardening of their radiation by surrounding leaky HII regions…

Astrophysics of Galaxies · Physics 2019-02-13 J. A. Weber , A. W. A. Pauldrach , T. L. Hoffmann

Cosmic Reionization On Computers (CROC) is a long-term program of numerical simulations of cosmic reionization. Its goal is to model fully self-consistently (albeit not necessarily from the first principles) all relevant physics, from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Nickolay Y. Gnedin

Recent years have brought more precise temperature measurements of the low-density intergalactic medium (IGM). These new measurements constrain the processes that heated the IGM, such as the reionization of H I and of He II. We present a…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-10 Phoebe R. Upton Sanderbeck , Anson D'Aloisio , Matthew J. McQuinn

We combine fast radiative transfer calculations with high resolution hydrodynamical simulations to study an epoch of early hydrogen reionisation by primordial stellar sources at redshifts 15<z<30. With relatively conservative assumptions,…

Astrophysics · Physics 2009-11-10 Aaron Sokasian , Naoki Yoshida , Tom Abel , Lars Hernquist , Volker Springel

Coupled radiative-hydrodynamics simulations of the epoch of reionization aim to reproduce the propagation of ionization fronts during the transition before the overlap of HII regions. Many of these simulations use moment-based methods to…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-13 Nicolas Deparis , Dominique Aubert , Pierre Ocvirk , Jonathan Chardin , Joseph Lewis

Lyman limit systems (LLSs) are dense hydrogen clouds with high enough HI column densities to absorb Lyman continuum photons emitted from distant quasars. Their high column densities imply an origin in dense environments; however, the…

Astrophysics of Galaxies · Physics 2024-03-04 Jiawen Fan , Hanjue Zhu , Camille Avestruz , Nickolay Y. Gnedin

We have run a new suite of simulations that solve hydrodynamics and radiative transfer simultaneously to study helium II reionization. Our suite of simulations employs various models for populating quasars inside of dark matter halos, which…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-11 Paul La Plante , Hy Trac , Rupert Croft , Renyue Cen

We present an efficient method to generate large simulations of the Epoch of Reionization (EoR) without the need for a full 3-dimensional radiative transfer code. Large dark-matter-only simulations are post-processed to produce maps of the…

QSO near-zones are an important probe of the the ionization state of the IGM at z ~ 6-7, at the end of reionization. We present here high-resolution cosmological 3D radiative transfer simulations of QSO environments for a wide range of host…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Laura C. Keating , Martin G. Haehnelt , Sebastiano Cantalupo , Ewald Puchwein

We present a method to construct semi-numerical ``simulations'', which can efficiently generate realizations of halo distributions and ionization maps at high redshifts. Our procedure combines an excursion-set approach with first-order…

Astrophysics · Physics 2009-11-13 Andrei Mesinger , Steven Furlanetto

The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and photoevaporating them. This feedback of universal…

Astrophysics · Physics 2007-05-23 Paul R. Shapiro , Alejandro C. Raga

We investigate the properties of cosmological ionization fronts during the Epoch of Reionization using the CROC simulations. By analyzing reionization timing maps, we characterize ionization front velocities and curvatures and their…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-29 Hanjue Zhu , Nickolay Y. Gnedin

The physical state of the intergalactic medium can be probed in great detail with the intervening absorption systems seen in quasar spectra. The properties of the Hydrogen absorbers depend on many cosmological parameters, such as the…

Astrophysics · Physics 2009-11-11 Tom Theuns

When modelling the ionisation of gas in the intergalactic medium after reionisation, it is standard practice to assume a uniform radiation background. This assumption is not always appropriate; models with radiative transfer show that…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-02 Teresita Suarez , Andrew Pontzen