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Related papers: Modeling Reionization in a Bursty Universe

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Large-scale reionization simulations are described which combine the results of cosmological N-body simulations that model the evolving density and velocity fields and identify the galactic halo sources, with ray-tracing radiative transfer…

We use the \textsc{astraeus} framework, that couples an N-body simulation with a semi-analytic model for galaxy formation and a semi-numerical model for reionization, to quantify the star formation histories (SFHs) of galaxies in the first…

Astrophysics of Galaxies · Physics 2021-11-03 Laurent Legrand , Anne Hutter , Pratika Dayal , Graziano Ucci , Stefan Gottlöber , Gustavo Yepes

The elevated UV luminosity functions (UVLF) from recent James Webb Space Telescope (JWST) have challenged the viability of existing theoretical models. To address this, we use a semi-analytical framework -- which couples a physically…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-21 Ankita Bera , Sultan Hassan , Robert Feldmann , Romeel Davé , Kristian Finlator

We present a new, on-the-fly photon flux and absorption tracer algorithm designed to directly measure the contribution of different source populations to the metagalactic UV background and to the ionisation fraction of gas in the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Harley Katz , Taysun Kimm , Martin Haehnelt , Debora Sijacki , Joakim Rosdahl , Jeremy Blaizot

A number of current and future experiments aim to detect the reionization of neutral hydrogen by the first stars and galaxies in the Universe via the redshifted 21cm line. Using the \textsc{BlueTides} simulation, we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-20 James E Davies , Rupert A. Croft , Tiziana Di-Matteo , Bradley Greig , Yu Feng , Stuart Wyithe

We explore the ability of measurements of the 21-cm power spectrum during reionization to enable the simultaneous reconstruction of the reionization history and the properties of the ionizing sources. For various sets of simulated 21-cm…

Astrophysics · Physics 2015-05-13 Rennan Barkana

To advance our understanding of massive star formation, it is essential to perform a comprehensive suite of simulations that explore the relevant parameter space and include enough physics to enable a comparison with observational data. We…

Astrophysics of Galaxies · Physics 2025-11-19 Birka Zimmermann , Stefanie Walch , Seamus D. Clarke , Richard Wünsch , Andre Klepitko

Observations on the high-redshift galaxies at $z>6$ imply that their ionizing emissivity is unable to fully reionize the Universe at $z\sim 6$. Either a high escape fraction of ionizing photons from these galaxies or a large population of…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-02 Jing-Meng Hao , Ye-Fei Yuan , Lei Wang

Based on the gamma-ray burst (GRB) event rate at redshifts of $4 \leq z \leq 12$, which is assessed by the spectral peak energy-to-luminosity relation recently found by Yonetoku et al., we observationally derive the star formation rate…

Astrophysics · Physics 2009-11-11 T. Murakami , D. Yonetoku , M. Umemura , T. Matsubayashi , R. Yamazaki

Semi-numeric methods have made it possible to efficiently model the epoch of reionisation (EoR). While most implementations involve a reduction to a simple three-parameter model, we introduce a new mass-dependent ionising efficiency…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-12 Daegene Koh , John H. Wise

It has been claimed that traditional models struggle to explain the tentative detection of the 21\,cm absorption trough centered at $z\sim17$ measured by the EDGES collaboration. On the other hand, it has been shown that the EDGES results…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-31 Ankita Bera , Sultan Hassan , Aaron Smith , Renyue Cen , Enrico Garaldi , Rahul Kannan , Mark Vogelsberger

[abridged]We use 3D cosmological simulations with radiative transfer to study the formation and evolution of the first galaxies in a LCDM cosmology. We find that the first luminous objects ("small-halos") are characterized by a bursting…

Astrophysics · Physics 2009-11-07 Massimo Ricotti , Nickolay Y. Gnedin , J. Michael Shull

We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6<z<8. These galaxies were selected from new deep near-infrared HST imaging from the CANDELS, HUDF09 and ERS programs. In contrast to…

A key physical quantity during reionization is the size of HII regions. Previous studies found a characteristic bubble size which increases rapidly during reionization, with apparent agreement between simulations and analytic excursion set…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-07 Yin Lin , S. Peng Oh , Steven R. Furlanetto , P. M. Sutter

We use a semi-analytical model to study the impact of reionization, and the associated radiative feedback, on galaxy formation. Two feedback models have been considered: (i) a standard prescription, according to which star formation is…

Astrophysics · Physics 2009-11-13 R. Schneider , R. Salvaterra , T. Roy Choudhury , A. Ferrara , C. Burigana , L. A. Popa

The history of the transition from a neutral intergalactic medium (IGM) to one that is almost fully ionized can reveal the character of cosmological ionizing sources and set important constraints on the stellar birthrate at high redshifts.…

Astrophysics · Physics 2007-05-23 Piero Madau

Recent observations show that the measured rates of star formation in the early universe are insufficient to produce re-ionization, and therefore, another source of ionizing photons is required. In this \emph{Letter}, we examine the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Michael A. Dopita , Lawrence M. Krauss , Ralph S. Sutherland , Chiaki Kobayashi , Charles H. Lineweaver

We perform an analysis of the cosmic reionization in the standard cold dark matter (CDM) paradigm and in alternative dark matter scenarios. Building upon the work of Corasaniti et al. (2017), we predict the reionization history for CDM, for…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 Isabella P. Carucci , Pier-Stefano Corasaniti

(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

We present a model for the evolution of the galaxy ultraviolet (UV) luminosity function (LF) across cosmic time where star formation is linked to the assembly of dark matter halos under the assumption of a mass dependent, but redshift…

Astrophysics of Galaxies · Physics 2015-12-03 Charlotte Mason , Michele Trenti , Tommaso Treu