English
Related papers

Related papers: Reionization on Large Scales I: A Parametric Model…

200 papers

Preparing for the first detection of the cosmic 21-cm signal from large-scale interferometer experiments requires rigorous testing of the data analysis and reduction pipelines. To validate that these pipelines do not erroneously remove or…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Bradley Greig , J. Stuart B. Wyithe , Steven G. Murray , Simon J. Mutch , Cathryn M. Trott

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

A variety of approximate schemes for modelling the low-density Intergalactic Medium (IGM) in the high-redshift Universe is compared to the results of a large high-resolution hydro-dynamical simulation. These schemes use either an analytical…

Astrophysics · Physics 2011-07-19 M. Viel , S. Matarrese , H. J. Mo , Tom Theuns , M. G. Haehnelt

The neutral hydrogen (HI) and its 21 cm line are promising probes to the reionization process of the intergalactic medium (IGM). To use this probe effectively, it is imperative to have a good understanding on how the neutral hydrogen traces…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Wenxiao Xu , Yidong Xu , Bin Yue , Ilian T Iliev , Hy Trac , Liang Gao , Xuelei Chen

We explore the ability of observations of the global brightness temperature of the 21-cm signal to constrain the reionization history and the properties of the ionizing sources. In order to describe the reionization signal, we employ either…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Andrea Morandi , Rennan Barkana

We simulate a plausible cosmological model in considerable physical and numerical detail through the successive phases of reheating (at 10<z<20), formation of Pop III stars at z=15 (due to molecular hydrogen cooling), with subsequent…

Astrophysics · Physics 2009-10-28 Nickolay Y. Gnedin , Jeremiah P. Ostriker

We present and test a framework that models the three-dimensional distribution of mass in the Universe as a function of cosmological and astrophysical parameters. Our approach combines two different techniques: a rescaling algorithm that…

Observations of the Epoch of Reionization (EoR) have the potential to answer long-standing questions of astrophysical interest regarding the nature of the first luminous sources and their effects on the intergalactic medium (IGM). We…

The epoch of hydrogen reionization is complete by $z=5$, but its progression at higher redshifts is uncertain. Measurements of Ly$\alpha$ forest opacity show large scatter at $z<6$, suggestive of spatial fluctuations in neutral fraction…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-05 Caitlin C. Doughty , Joseph F. Hennawi , Jose Oñorbe , Frederick B. Davies , Zarija Lukić

Traditional large-scale models of reionization usually employ simple deterministic relations between halo mass and luminosity to predict how reionization proceeds. We here examine the impact on modelling reionization of using more detailed…

Recently, we have presented the first large-scale radiative transfer simulations of reionization. Here we present new simulations which extend the source halo mass range downward to 10^8M_solar, to capture the full range of halo masses…

Astrophysics · Physics 2008-11-26 Ilian T. Iliev , Garrelt Mellema , Paul R. Shapiro , Ue-Li Pen

Observations of galaxy luminosity function at high redshifts typically focus on fields of view of limited sizes preferentially containing bright sources. These regions possibly are overdense and hence biased with respect to the globally…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Girish Kulkarni , T. Roy Choudhury

(Abridged) Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include non-equilibrium primordial…

Astrophysics · Physics 2009-11-13 John H. Wise , Tom Abel

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…

The Cosmic Dark Ages and the Epoch of Reionization constitute a crucial missing link in our understanding of the evolution of the intergalactic medium and the formation and evolution of galaxies. Due to the complex nature of this global…

Astrophysics · Physics 2008-06-19 Ilian T. Iliev , Paul R. Shapiro , Garrelt Mellema , Hugh Merz , Ue-Li Pen

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

In recent years, deep learning models have been successfully employed for augmenting low-resolution cosmological simulations with small-scale information, a task known as "super-resolution". So far, these cosmological super-resolution…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-14 Andreas Schanz , Florian List , Oliver Hahn

We use high-resolution simulations of cosmological volumes to model galaxy formation at high-redshift, with the goal of studying the photon budget for reionization. We demonstrate that galaxy formation models that include a strong,…

Astrophysics of Galaxies · Physics 2014-08-13 Alan R. Duffy , J. Stuart B. Wyithe , Simon J. Mutch , Gregory B. Poole

Extending the formalism of Datta, Bharadwaj & Choudhury (2007) for detecting ionized bubbles in redshifted 21 cm maps using a matched-filtering technique, we use different simulations to analyze the impact of HI fluctuations outside the…

Astrophysics · Physics 2009-11-13 Kanan K. Datta , Suman Majumdar , Somnath Bharadwaj , T. Roy Choudhury

We present an improved matched filter method for detecting large ionized regions in 21 cm observations of the Epoch of Reionization. In addition to detection, the method constrains the properties of these regions, offering insights into the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-23 Rutvik Ashish Mahajan , Raghunath Ghara , Nishant Pradeep Deo , Arnab Mishra