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Related papers: Narrow escape: how ionizing photons escape from di…

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We use the first data release from the SINGG H-alpha survey of HI-selected galaxies to study the quantitative behavior of the diffuse, warm ionized medium (WIM) across the range of properties represented by these 109 galaxies. The mean…

A large number of high-redshift galaxies have been discovered via their narrow-band Lya line or broad-band continuum colors in recent years. The nature of the escaping process of photons from these early galaxies is crucial to understanding…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-16 Hidenobu Yajima , Yuexing Li , Qirong Zhu , Tom Abel , Caryl Gronwall , Robin Ciardullo

High-resolution numerical simulations including feedback and aimed at calculating the escape fraction (fesc) of hydrogen-ionizing photons often assume stellar radiation based on single-stellar population synthesis models. However, strong…

Astrophysics of Galaxies · Physics 2020-09-30 Amy Secunda , Renyue Cen , Taysun Kimm , Ylva Gotberg , Selma E. de Mink

Escaping Lyman continuum photons from galaxies likely reionized the intergalactic medium at redshifts $z\gtrsim6$. However, the Lyman continuum is not directly observable at these redshifts and secondary indicators of Lyman continuum escape…

We present a new method to quantify the value of the escape fraction of ionizing photons, and the existence of ultra-faint galaxies clustered around brighter objects during the epoch of cosmic reionization, using the diffuse Ly$\alpha$,…

Astrophysics of Galaxies · Physics 2017-09-06 Lluís Mas-Ribas , Joseph F. Hennawi , Mark Dijkstra , Frederick B. Davies , Jonathan Stern , Hans-Walter Rix

The escape fraction of hydrogen ionizing photons (f_esc) from galaxies has been suggested to be evolving with time, but the picture is far from clear. While evidence for significant escape fractions has been found at high redshifts in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Elisabet Leitet , Nils Bergvall , Matthew Hayes , Staffan Linné , Erik Zackrisson

Most of the hydrogen in the intergalactic medium (IGM) was rapidly ionized at high-redshifts. While observations have established that reionization occurred, observational constraints on the emissivity of ionizing photons at high-redshift…

In this work, we investigate upper limits on the global escape fraction of ionizing photons ($f_{\rm esc/global}^{\rm abs}$) from a sample of galaxies probed for Lyman-continuum (LyC) emission characterized as non-LyC and LyC leakers. We…

Astrophysics of Galaxies · Physics 2021-09-27 U. Meštrić , E. V. Ryan-Weber , J. Cooke , R. Bassett , L. J. Prichard , M. Rafelski

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 escaping ionising efficiency from galaxies, $f_{\rm esc}\xi_{\rm ion}$, is a crucial ingredient for understanding their contribution to hydrogen reionisation, but both of its components, $f_{\rm{esc}}$ and $\xi_{\rm{ion}}$, are…

Astrophysics of Galaxies · Physics 2024-09-16 Sarah E. I. Bosman , Frederick B. Davies

The fate of ionizing radiation is vital for understanding cosmic ionization, energy budgets in the interstellar and intergalactic medium, and star formation rate indicators. The low observed escape fractions of ionizing radiation have not…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 D. J. Hanish , M. S. Oey , J. R. Rigby , D. F. de Mello , J. C. Lee

Early results from JWST suggest that epoch-of-reionization (EoR) galaxies produce copious ionizing photons, which, if they escape efficiently, could cause reionization to occur too early. We study this problem using \jwst\ imaging and prism…

The Epoch of Reionization (EoR) provides critical insights into the role of early galaxies in shaping the ionization state of the universe. However, because of the opacity of the intergalactic medium, it is often not possible to make direct…

Hydrogen in the Universe was (re)ionised between redshifts $z \approx 10$ and $z \approx 6$. The nature of the sources of the ionising radiation is hotly debated, with faint galaxies below current detection limits regarded as prime…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Mahavir Sharma , Tom Theuns , Carlos S. Frenk , Richard G. Bower , Robert A. Crain , Matthieu Schaller , Joop Schaye

One of the most important parameters in characterizing the Epoch of Reionization, the escape fraction of ionizing photons, $f_\mathrm{esc}$, remains unconstrained both observationally and theoretically. With recent work highlighting the…

Astrophysics of Galaxies · Physics 2019-07-16 Jacob Seiler , Anne Hutter , Manodeep Sinha , Darren Croton

In this article we first outline the mounting evidence that a significant fraction of the ionizing photons emitted by OB stars within HII regions escape from their immediate surroundings and explain how an HII region structure containing…

Astrophysics · Physics 2009-11-11 C. Giammanco , J. E. Beckman , B. Cedres

JWST is providing constraints on the history of reionization owing to its ability to detect faint galaxies at $z\gg6$. Modeling this history requires understanding both the ionizing photon production rate ($\xi_{\rm ion}$) and the fraction…

Astrophysics of Galaxies · Physics 2025-01-22 Nicholas Choustikov , Richard Stiskalek , Aayush Saxena , Harley Katz , Julien Devriendt , Adrianne Slyz

Recent observations of galaxies at $z \gtrsim 7$, along with the low value of the electron scattering optical depth measured by the Planck mission, make galaxies plausible as dominant sources of ionizing photons during the epoch of…

The dark ages of the Universe end with the formation of the first generation of stars residing in primeval galaxies. These objects were the first to produce ultraviolet ionizing photons in a period when the cosmic gas changed from a neutral…

Instrumentation and Methods for Astrophysics · Physics 2019-01-15 M. W. Hattab , R. S. de Souza , B. Ciardi , J. -P. Paardekooper , S. Khochfar , C. Dalla Vecchia

A thorough analysis of well studied giant HII regions on galactic discs for which we know the ionizing stellar population, the gas metallicity and the Wolf-Rayet population, leads to photoionization models which can only match all observed…

Astrophysics · Physics 2007-05-23 M. Castellanos , A. I. Diaz , G. Tenorio-Tagle