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Related papers: How Do Ionizing Photons Escape from Star-Forming G…

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We measure escape fractions, $f_{\rm esc}$, of ionizing radiation from galaxies in the SPHINX suite of cosmological radiation-hydrodynamical simulations of reionization, resolving halos with $M_{\rm vir} \gtrapprox 7.5 \times 10^7 \…

One of the key questions in observational cosmology is the identification of the sources responsible for ionisation of the Universe after the cosmic Dark Ages, when the baryonic matter was neutral. The currently identified distant galaxies…

Astrophysics of Galaxies · Physics 2016-01-14 Y. I. Izotov , I. Orlitova , D. Schaerer , T. X. Thuan , A. Verhamme , N. Guseva , G. Worseck

The Universe's dark ages end with the formation of the first generation of galaxies. These objects start emitting ultraviolet radiation that carves out ionized regions around them. After a sufficient number of ionizing sources have formed,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Saleem Zaroubi

The source responsible for reionizing the universe at z > 6 remains uncertain. While an energetically adequate population of star-forming galaxies may be in place, it is unknown whether a large enough fraction of their ionizing radiation…

We use a three-dimensional radiation transfer code to calculate the steady-state escape fraction of ionizing photons from disk galaxies as a function of redshift and galaxy mass. The gaseous disks are assumed to be isothermal (with a sound…

Astrophysics · Physics 2009-10-31 Kenneth Wood , Abraham Loeb

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

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

Quantifying the physical conditions that allow radiation emitted shortward of the hydrogen ionization edge at 911.7 {\AA} to escape the first collapsed objects and ultimately reionize the universe is a compelling problem for astrophysics.…

Cosmic reionization is thought to be primarily fueled by the first generations of galaxies. We examine their stellar and gaseous properties, focusing on the star formation rates and the escape of ionizing photons, as a function of halo…

Astrophysics of Galaxies · Physics 2016-12-14 Hao Xu , John H. Wise , Michael L. Norman , Kyungjin Ahn , Brian W. O'Shea

A fundamental requirement for reionizing the Universe is that a sufficient fraction of the ionizing photons emitted by galaxies successfully escapes into the intergalactic medium. However, due to the scarcity of high-redshift observational…

We model the escape of ionizing radiation from high-redshift galaxies using high-resolution Adaptive Mesh Refinement N-body + hydrodynamics simulations. Our simulations include time-dependent and spatially-resolved transfer of ionizing…

Astrophysics · Physics 2010-11-11 Nickolay Y. Gnedin , Andrey V. Kravtsov , Hsiao-Wen Chen

We study the escape of Lyman continuum radiation from the disks of dwarf starburst galaxies, with and without supershells, by solving the radiation transfer problem of stellar radiation through them. We model disks with Md=10^8-10Msun, with…

Astrophysics · Physics 2009-11-07 Akimi Fujita , Crystal Martin , Mordecai-Mark Mac Low , Tom Abel

The escape fraction, f_{esc}, of ionizing photons from high-redshift galaxies is a key parameter to understand cosmic reionization and star formation history. Yet, in spite of many efforts, it remains largely uncertain. We propose a novel,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Sourav Mitra , Andrea Ferrara , T. Roy Choudhury

The contribution of stars in galaxies to cosmic reionisation depends on the star formation history in the Universe, the abundance of galaxies during reionisation, the escape fraction of ionising photons and the clumping factor of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jan-Pieter Paardekooper , Sadegh Khochfar , Claudio Dalla Vecchia

Some Lyman continuum photons are likely to escape from most galaxies, and these can play an important role in ionizing gas around and between galaxies, including gas that gives rise to Lyman alpha absorption. Thus the gas surrounding…

The fate of ionizing radiation in starburst galaxies is key to understanding cosmic reionization. However, the galactic parameters on which the escape fraction of ionizing radiation depend are not well understood. Ionization-parameter…

Astrophysics of Galaxies · Physics 2015-06-17 Jordan Zastrow , M. S. Oey , Sylvain Veilleux , Michael McDonald

Star-forming galaxies are considered the likeliest source of the H I ionizing Lyman Continuum (LyC) photons that reionized the intergalactic medium at high redshifts. However, above z >~ 6, the neutral intergalactic medium prevents direct…

Using our cosmological radiative transfer code, we study the implications of the updated QSO emissivity and star formation history for the escape fraction (f_esc) of hydrogen ionizing photons from galaxies. We estimate the f_esc that is…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-13 Vikram Khaire , Raghunathan Srianand , Tirthankar Roy Choudhury , Prakash Gaikwad

The processes allowing the escape of ionizing photons from galaxies into the intergalactic medium are poorly known. To understand how Lyman continuum (LyC) photons escape galaxies, we constrain the HI covering fractions and column densities…

Astrophysics of Galaxies · Physics 2018-08-08 Simon Gazagnes , John Chisholm , Daniel Schaerer , Anne Verhamme , Jane R. Rigby , Matthew Bayliss

The goal of searching back in cosmic time to find star formation during the epoch of reionization will soon be within reach. We assess the detectability of high-redshift galaxies by combining cosmological hydrodynamic simulations of galaxy…