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Related papers: Re-ionizing the Universe without Stars

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Early galaxies were the radiation source for reionization, with the photoheating feedback from the reionization process expected to reduce the efficiency of star formation in low mass haloes. Hence, to fully understand reionization and…

We incorporate quasars into an analytic model to describe the reheating and reionization of the universe. In combination with a previous study of galaxies and Lyman-$\alpha$ clouds, we are able to provide a unified description of structure…

Astrophysics · Physics 2007-05-23 P. Valageas , J. Silk

We use cosmological simulations to study the X-ray ionisation and heating of the intergalactic medium by an early population of accreting black holes. By considering observational constraints from the X-ray background, we find an upper…

Astrophysics · Physics 2009-11-10 Massimo Ricotti , Jeremiah P. Ostriker , Nickolay Y. Gnedin

The early reionization of the intergalactic medium, which is favored from the WMAP temperature-polarization cross-correlations, contests the validity of the standard scenario of structure formation in the cold dark matter cosmogony. It is…

Astrophysics · Physics 2009-11-11 Hiroyuki Tashiro , Naoshi Sugiyama

The cosmic star formation histories are evaluated for different minimum masses of the initial halo structures, with allowance for realistic gas outflows. With a minimum halo mass of 10^{7} - 10^{8} M_odot and a moderate outflow efficiency,…

Astrophysics · Physics 2009-09-15 Frederic Daigne , Keith A. Olive , Joe Silk , Felix Stoehr , Elisabeth Vangioni

Compact, low-mass galaxies with strong nebular emission are considered promising candidates for efficient ionizing photon production and escape. We present a spatially resolved analysis of 189 galaxies at redshifts $z \sim 6.7-7.6$ in JADES…

Astrophysics of Galaxies · Physics 2025-07-23 Cheqiu Lyu , Enci Wang , Junxian Wang , Cheng Jia , Jie Song , Yangyao Chen , Zeyu Chen , Haoran Yu , Chengyu Ma , Jinyang Wang , Yifan Wang , Xu Kong

An ionizing UV background (UVB) inhibits gas accretion and photo-evaporates gas from the shallow potential wells of small, dwarf galaxies. During cosmological reionization, this effect can result in negative feedback: suppressing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Emanuele Sobacchi , Andrei Mesinger

We present self-consistent radiation hydrodynamic simulations of hydrogen reionization performed with Arepo-RT complemented by a state-of-the-art galaxy formation model. We examine how photoheating feedback, due to reionization, shapes the…

Astrophysics of Galaxies · Physics 2019-06-25 Xiaohan Wu , Rahul Kannan , Federico Marinacci , Mark Vogelsberger , Lars Hernquist

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

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…

In popular cold dark matter cosmological scenarios, stars may have first appeared in significant numbers around a redshift of 10 or so, as the gas within protogalactic halos with virial temperatures in excess of 20,000 K (corresponding to…

Astrophysics · Physics 2007-05-23 Piero Madau

Recent results have suggested that active galactic nuclei (AGN) could provide enough photons to reionise the Universe. We assess the viability of this scenario using a semi-numerical framework for modeling reionisation, to which we add a…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-23 Sultan Hassan , Romeel Davé , Sourav Mitra , Kristian Finlator , Benedetta Ciardi , Mario G. Santos

We calculate the contribution to the cosmic infrared background from very massive metal-free stars at high redshift. We explore two plausible star-formation models and two limiting cases for the reprocessing of the ionizing stellar…

Astrophysics · Physics 2009-11-07 Michael R. Santos , Volker Bromm , Marc Kamionkowski

Probing the growth of structure from the epoch of hydrogen recombination to the formation of the first stars and galaxies is one of the most important uncharted areas of observational cosmology. Far-IR spectroscopy covering $\lambda$…

Population III stars can regulate star formation in the primordial Universe in several ways. They can ionize nearby halos, and even if their ionizing photons are trapped by their own halos, their Lyman-Werner (LW) photons can still escape…

Astrophysics of Galaxies · Physics 2015-10-21 Anna T. P. Schauer , Daniel J. Whalen , Simon C. O. Glover , Ralf S. Klessen

We explore the impacts of ultraviolet (UV) radiation feedback on galaxies during the epoch of reionisation by cosmological simulations in which hydrodynamics and the transfer of the H and He ionising photons are consistently coupled.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Kenji Hasegawa , Benoit Semelin

The global history of reionization was shaped by the relative amounts of starlight released by three halo mass groups: atomic-cooling halos (ACHs) with virial temperatures Tvir > 10^4 K, either (1) massive enough to form stars even after…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Kyungjin Ahn , Paul R. Shapiro

The epoch of reionization (6 < z < 10) marks the period in our universe when the first large galaxies grew to fruition, and began to affect the universe around them. Massive stars, and potentially accreting supermassive black holes, filled…

Molecular clouds interacting with supernova remnants may be subject to a greatly enhanced irradiation by cosmic rays produced at the shocked interface between the ejecta and the molecular gas. Over the past decade, broad-band observations…

Astrophysics · Physics 2009-11-11 M. Fatuzzo , F. C. Adams , F. Melia

We study the observed cosmic ionizing background as a constraint on the nature of the sources responsible for the reionization of the Universe. In earlier work, we showed that extrapolations of the Ultra-Violet Luminosity Function (LF) of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Fabio Fontanot , Stefano Cristiani , Christoph Pfrommer , Guido Cupani , Eros Vanzella