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Related papers: Modeling Reionization in a Bursty Universe

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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

We present first results from three-dimensional hydrodynamic simulations of the high redshift formation of dwarf galaxies. The simulations use an Eulerian adaptive mesh refinement technique to follow the non-equilibrium chemistry of…

Astrophysics · Physics 2009-11-07 Konstantinos Tassis , Tom Abel , Greg L. Bryan , Michael L. Norman

The JWST early release data show unexpected high stellar mass densities of massive galaxies at $7<z<11$, a high star formation efficiency is probably needed to explain this. However, such a high star formation efficiency would greatly…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Yan Gong , Bin Yue , Ye Cao , Xuelei Chen

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

JWST spectra revealing Lyman-$\alpha$ (Ly$\alpha$) absorption in $z\sim 5-14$ galaxies offer a unique probe of reionization's earliest stages. However, disentangling absorption by the increasingly neutral intergalactic medium (IGM) from…

A very large dynamic range with simultaneous capture of both large- and small-scales in the simulations of cosmic structures is required for correct modelling of many cosmological phenomena, particularly at high redshift. This is not always…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Ainulnabilah Nasirudin , Ilian T. Iliev , Kyungjin Ahn

The current models of early star and galaxy formation are based upon the hierarchical growth of dark matter halos, within which the baryons condense into stars after cooling down from a hot diffuse phase. The latter is replenished by infall…

Astrophysics · Physics 2009-10-31 A. Cavaliere , R. Giacconi , N. Menci

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…

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

We measure the effective optical depth of HeII Ly\alpha\ absorption \tau$_\mathsf{eff,HeII}$ at 2.3<z<3.5 in 17 UV-transmitting quasars observed with UV spectrographs on the Hubble Space Telescope (HST). The median \tau$_\mathsf{eff,HeII}$…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-30 Gábor Worseck , J. Xavier Prochaska , Joseph F. Hennawi , Matthew McQuinn

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…

JWST have revealed temporarily-quenched and ultraviolet-luminous galaxies in the early universe, suggesting enhanced star formation stochasticity. Verifying this hypothesis is critical, yet challenging; outshining, wherein light from young…

In recent years, several analytic models have demonstrated that simple assumptions about halo growth and feedback-regulated star formation can match the (limited) existing observational data on galaxies at z>6. By extending such models, we…

Astrophysics of Galaxies · Physics 2022-02-16 Steven R. Furlanetto , Jordan Mirocha

Using results from high-resolution galaxy formation simulations in a standard Lambda-CDM cosmology and a fully conservative multi-resolution radiative transfer code around point sources, we compute the energy-dependent escape fraction of…

Astrophysics · Physics 2011-02-11 Alexei O. Razoumov , Jesper Sommer-Larsen

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

The reionization of cosmic hydrogen marks a critical juncture in the history of structure formation in the universe. Here we present a new formulation of the standard reionization equation for the evolution of the volume-averaged HII…

Astrophysics of Galaxies · Physics 2017-12-13 Piero Madau

Low mass galaxies are thought to provide the bulk of the ionizing radiation necessary to reionize the Universe. The amount of photons escaping the galaxies is poorly constrained theoretically, and difficult to measure observationally. Yet…

Astrophysics of Galaxies · Physics 2017-05-03 Maxime Trebitsch , Jérémy Blaizot , Joakim Rosdahl , Julien Devriendt , Adrianne Slyz

JWST is unveiling a surprising lack of evolution in the number densities of ultraviolet-selected (UV) galaxies at redshift $z\gtrsim 10$. At the same time, observations and simulations are providing evidence for highly bursty star formation…

Astrophysics of Galaxies · Physics 2025-05-21 Viola Gelli , Charlotte Mason , Christopher C. Hayward

Using 3D radiative transfer calculations on the reionization of an inhomogeneous universe, QSO absorption line systems are simulated and they are compared with observations of Ly$\alpha$ continuum depression at high redshifts. By this…

Astrophysics · Physics 2007-05-23 M. Umemura , T. Nakamoto , H. Susa

We explore the impact of cosmic reionization on nearby isolated dwarf galaxies using a compilation of SFHs estimated from deep HST data and a cosmological hydrodynamical simulation of the Local Group. The nearby dwarfs show a wide diversity…

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