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Related papers: Is Double Reionization Physically Plausible?

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Current observations suggest that the universe was reionized sometime before z~6. One way to observe this epoch of the universe is through the Near Infrared Background (NIRB), which contains information about galaxies which may be too faint…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-18 Elizabeth R. Fernandez , Ilian T. Iliev , Eiichiro Komatsu , Paul R. Shapiro

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 assess a model of late cosmic reionization in which the ionizing background radiation arises entirely from high redshift quasars and other active galactic nuclei (AGNs). The low optical depth to Thomson scattering reported by the Planck…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Piero Madau , Francesco Haardt

After the so-called cosmic recombination, the expanding universe entered into a period of darkness since most of the matter was in a neutral state. About a billion years later, however, the intergalactic space was once again ionized. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-15 Matias Tueros , Maria Victoria del Valle , Gustavo Esteban Romero

Density inhomogeneity in the intergalactic medium (IGM) can boost the recombination rate of ionized gas substantially, affecting the growth of HII regions during reionization. Previous attempts to quantify this effect typically failed to…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 Hyunbae Park , Paul R. Shapiro , Jun-hwan Choi , Naoki Yoshida , Shingo Hirano , Kyungjin Ahn

Magnetic fields are ubiquitous in the Universe. They seem to be present at virtually all scales and all epochs. Yet, whether the fields on cosmological scales are of astrophysical or cosmological origin remains an open major problem. Here…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-28 Jean-Baptiste Durrive , Hiroyuki Tashiro , Mathieu Langer , Naoshi Sugiyama

With improving telescopes, it may now be possible to observe the Epoch of Reionization in multiple ways. We examine two of these observables - the excess light in the near-infrared background that may be due to high redshift stars and…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-19 Elizabeth R. Fernandez , Saleem Zaroubi , Ilian T. Iliev , Garrelt Mellema , Vibor Jelic

We discuss new constraints on the epoch of cosmic reionization and test the assumption that most of the ionizing photons responsible arose from high redshift star-forming galaxies. Good progress has been made in charting the end of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Brant E. Robertson , Richard S. Ellis , Steven R. Furlanetto , James S. Dunlop

The epoch of reionization probes the state of our universe when the very first stars formed and ionized the hydrogen atoms in the surrounding medium. Since the epoch has not yet been probed observationally, it is often called the "final…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-20 Tirthankar Roy Choudhury

We use the photon flux and absorption tracer algorithm presented in Katz et al.~2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-05 Harley Katz , Taysun Kimm , Martin G. Haehnelt , Debora Sijacki , Joakim Rosdahl , Jeremy Blaizot

One of the main challenges facing standard hierarchical structure formation models is that the predicted abundance of galactic subhalos with circular velocities of 10-30 km/s is an order of magnitude higher than the number of satellites…

Astrophysics · Physics 2009-10-31 James S. Bullock , Andrey V. Kravtsov , David H. Weinberg

Reionisation in the early Universe is likely driven by dwarf galaxies. Using cosmological radiation-hydrodynamic simulations, we study star formation and the escape of Lyman continuum (LyC) photons from mini-haloes with $M_{\rm halo} \le…

Astrophysics of Galaxies · Physics 2017-01-18 Taysun Kimm , Harley Katz , Martin Haehnelt , Joakim Rosdahl , Julien Devriendt , Adrianne Slyz

Reionization, the only phase transition in the Universe since recombination, is a key event in the cosmic history of baryonic matter. We derive, in the context of the large-scale bias expansion, the imprints of the epoch of reionization in…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Fabian Schmidt , Florian Beutler

Cosmic Microwave Background temperature and polarization anisotropies from Planck have estimated a lower value of the optical depth to reionization ($\tau$) compared to WMAP. A significant period in the reionization history would then fall…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Dhiraj Kumar Hazra , Daniela Paoletti , Fabio Finelli , George F. Smoot

We develop an efficient method to study the effects of reionization history on the temperature-density relation of the intergalactic medium in the low density limit (overdensity less than 5). It is applied to the study of photo-reionization…

Astrophysics · Physics 2015-06-24 Lam Hui , Nickolay Y. Gnedin

One of the most sought-after signatures of reionization is a rapid increase in the ionizing background (usually measured through the Lyman-alpha optical depth toward distant quasars). Conventional wisdom associates this with the "overlap"…

Astrophysics · Physics 2009-11-13 Steven Furlanetto , Andrei Mesinger

The cosmic ultraviolet (UV) ionizing background impacts the formation of dwarf galaxies in the low-redshift universe (z=3) by suppressing gas infall into galactic halos with circular velocities up to v(circ)=75 km/s. Using a…

Astrophysics · Physics 2008-11-26 Mark Dijkstra , Zoltan Haiman , Martin J. Rees , David H. Weinberg

Cold dark matter models for galaxy formation predict that low-mass systems will be the first sites of star formation. As these objects have shallow gravitational potential wells, the subsequent growth of their stellar populations may be…

Astrophysics · Physics 2009-11-10 Eva K. Grebel , John S. Gallagher

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

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