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Related papers: Inhomogeneous HeII reionization in Hydrodynamic Si…

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We present the Technicolor Dawn simulations, a suite of cosmological radiation-hydrodynamic simulations of the first 1.2 billion years. By modeling a spatially-inhomogeneous UVB on-the-fly with 24 frequencies and resolving dark matter halos…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 Kristian Finlator , Laura Keating , Benjamin D. Oppenheimer , Romeel Davé , Erik Zackrisson

Cosmic Dawn II (CoDa II) is a new, fully-coupled radiation-hydrodynamics simulation of cosmic reionization and galaxy formation and their mutual impact, to redshift $z < 6$. With $4096^3$ particles and cells in a 94 Mpc box, it is large…

We present predictions for the reionization of the intergalactic medium by stars in high-redshift galaxies. We calculate ionizing luminosities of galaxies, including the effects of absorption by interstellar gas and dust on the escape…

Astrophysics · Physics 2009-10-31 A. J. Benson , Adi Nusser , Naoshi Sugiyama , C. G. Lacey

During the epoch of reionization a large number of photons were produced with frequencies below the hydrogen Lyman limit. After redshifting into the closest resonance, these photons underwent multiple scatterings with atoms. We examine the…

Astrophysics · Physics 2008-11-26 Leonid Chuzhoy , Paul R. Shapiro

Simulation codes for galaxy formation and evolution take on board as many physical processes as possible beyond the standard gravitational and hydrodynamical physics. Most of this extra physics takes place below the resolution level of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-17 Bert Vandenbroucke , Sven De Rijcke , Joeri Schroyen , Natalie Jachowicz

The first, self-consistent calculations are presented of the cosmological, H2-dissociating UV background produced during the epoch of reionization by the sources of reionization. Large-scale radiative transfer simulations of reionization…

Astrophysics · Physics 2015-05-13 Kyungjin Ahn , Paul R. Shapiro , Ilian T. Iliev , Garrelt Mellema , Ue-Li Pen

Models of the solar transition region made from lines other than those of helium cannot account for the strength of the helium lines. However, the collisional excitation rates of the helium resonance lines are unusually sensitive to the…

Astrophysics · Physics 2009-11-07 G. R. Smith , C. Jordan

We present an analysis of the evolution of the Lyman-series forest into the epoch of reionization using cosmological radiative transfer simulations in a scenario where reionization ends late. We explore models with different midpoints of…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 Laura C. Keating , Girish Kulkarni , Martin G. Haehnelt , Jonathan Chardin , Dominique Aubert

We use a set of cosmological simulations combined with radiative transfer calculations to investigate the distribution of neutral hydrogen in the post-reionization Universe. We assess the contributions from the metagalactic ionizing…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Alireza Rahmati , Andreas H. Pawlik , Milan Raičević , Joop Schaye

In a semi-numerical model of reionization, the evolution of ionization fraction is simulated approximately by the ionizing photon to baryon ratio criterion. In this paper we incorporate a semi-analytical model of galaxy formation based on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jie Zhou , Qi Guo , Gaochao Liu , Bin Yue , Yidong Xu , Xuelei Chen

The intergalactic medium (IGM) prior to the epoch of reionization consists mostly of neutral hydrogen gas. Ly-alpha photons produced by early stars resonantly scatter off hydrogen atoms, causing energy exchange between the radiation field…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Antonija Oklopcic , Christopher M. Hirata

We use a combination of analytic and numerical arguments to consider the impact of quasar photo-heating during HeII reionisation on the thermal evolution of the intergalactic medium (IGM). We demonstrate that rapid (\Delta z< 0.1-0.2),…

Astrophysics · Physics 2009-11-13 James S. Bolton , S. Peng Oh , Steven R. Furlanetto

We study the topology of reionization using accurate three-dimensional radiative transfer calculations post-processed on outputs from cosmological hydrodynamic simulations. In our simulations, reionization begins in overdense regions and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 K. Finlator , F. Ozel , R. Dave , B. D. Oppenheimer

Quasars that allow the study of IGM He II are very rare, since they must be at high redshift along sightlines free of substantial hydrogen absorption, but recent work has dramatically expanded the number of such quasars known. We analyze…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 David Syphers , Scott F. Anderson , Wei Zheng , Avery Meiksin , Daryl Haggard , Donald P. Schneider , Donald G. York

We present a new hybrid code for large volume, high resolution simulations of cosmic reionization, which utilizes a N-body algorithm for dark matter, physically motivated prescriptions for baryons and star formation, and an adaptive ray…

Astrophysics · Physics 2009-11-11 Hy Trac , Renyue Cen

Reionization is a process whereby hydrogen (and helium) in the Universe is ionized by the radiation from first luminous sources. Theoretically, the importance of the reionization lies in its close coupling with the formation of first cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 T. Roy Choudhury

It is possible that the properties of HII regions during reionization depend sensitively on many poorly constrained quantities (the nature of the ionizing sources, the clumpiness of the gas in the IGM, the degree to which photo-ionizing…

We develop a coupled model for the evolution of the global properties of the intergalactic medium (IGM) and the formation of galaxies, in the presence of a photoionizing background due to stars and quasars. We use this model to predict the…

Astrophysics · Physics 2008-11-26 A. J. Benson , C. G. Lacey , C. M. Baugh , S. Cole , C. S. Frenk

We present a semi-analytic model for the thermal and ionization history of the universe at 1000 >~ z >~ 3. This model incorporates much of the essential physics included in full-scale hydrodynamical simulations, such as (1) gravitational…

Astrophysics · Physics 2009-10-31 Weihsueh A. Chiu , Jeremiah P. Ostriker

Previously we identified a new class of early galaxy that we estimate contributes up to 30\% of the ionizing photons responsible for reionization. These are low mass halos in the range $M_h =10^{6.5}-10^{8} M_{\odot}$ that have been…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Michael L Norman , Pengfei Chen , John H Wise , Hao Xu