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相关论文: The escape fraction of ionizing photons from high …

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Observations of the Lyman-alpha forest and of high-redshift galaxies at z~5-10 imply that there were just enough photons to maintain the universe in an ionized state at z~5-6, indicating a "photon-starved" end to reionization. The ionizing…

宇宙学与河外天体物理 · 物理学 2015-06-11 Marcelo A. Alvarez , Kristian Finlator , Michele Trenti

We couple the DELPHI framework for galaxy formation with a model for the escape of ionizing photons to study both its variability with galaxy assembly and the resulting key reionization sources. In this model, leakage either occurs through…

星系天体物理 · 物理学 2023-06-28 Jonas Bremer , Pratika Dayal

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…

宇宙学与河外天体物理 · 物理学 2014-04-16 Hidenobu Yajima , Yuexing Li , Qirong Zhu , Tom Abel , Caryl Gronwall , Robin Ciardullo

The fraction of ionizing photons escaping from galaxies, $f_{esc}$, is at the same time a crucial parameter in modelling reionization and a very poorly known quantity, especially at high redshift. Recent observations are starting to…

In this work we investigate the dependence of the escape fraction of ionizing photons, $f_{\rm esc}$, on various galaxy and host halo properties during the epoch of reionization. We post-process the TNG50 magneto-hydrodynamical simulation…

星系天体物理 · 物理学 2023-03-29 Ivan Kostyuk , Dylan Nelson , Benedetta Ciardi , Martin Glatzle , Annalisa Pillepich

The physical origin of low escape fractions of ionizing radiation derived from massive star-forming galaxies at $z\sim3$-$4$ is not well understood. We perform idealised disc galaxy simulations to understand how galactic properties such as…

星系天体物理 · 物理学 2020-10-21 Taehwa Yoo , Taysun Kimm , Joakim Rosdahl

In order to assess the contribution of Lyman break galaxies (LBGs) and Lyman alpha emitters (LAEs) at redshifts 3<z<7 to the ionization of intergalactic medium (IGM), we investigate the escape fractions of ionizing photons from…

宇宙学与河外天体物理 · 物理学 2015-05-13 Hidenobu Yajima , Masayuki Umemura , Masao Mori , Taishi Nakamoto

In this work we investigate the properties of the sources that reionized the intergalactic medium (IGM) in the high-redshift Universe. Using a semi-analytical model aimed at reproducing galaxies and black holes in the first 1.5 Gyr of the…

The protagonists of cosmic reionization remain elusive. Faint star-forming galaxies are leading candidates because they are numerous and may have significant ionizing photon escape fractions ($f_{esc}$). Here we update this picture via an…

星系天体物理 · 物理学 2020-04-07 Rohan P. Naidu , Sandro Tacchella , Charlotte A. Mason , Sownak Bose , Pascal A. Oesch , Charlie Conroy

We have obtained deep Hubble Space Telescope far-UV images of 15 starburst galaxies at z~1.3 in the GOODS fields to search for escaping Lyman continuum photons. These are the deepest far-UV images m_{AB}=28.7, 3\sigma, 1" diameter) over…

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…

宇宙学与河外天体物理 · 物理学 2016-09-13 Vikram Khaire , Raghunathan Srianand , Tirthankar Roy Choudhury , Prakash Gaikwad

The observed number density of Lyman-alpha sources implies a minimum volume of the inter-galactic medium that must be ionized, in order to allow the Lyman-alpha photons to escape attenuation. We estimate this volume by assigning to each…

天体物理学 · 物理学 2009-11-11 Sangeeta Malhotra , James Rhoads

The fraction of ionizing photons that escape from young star-forming galaxies is one of the largest uncertainties in determining the role of galaxies in cosmic reionization. Yet traditional techniques for measuring this fraction are…

宇宙学与河外天体物理 · 物理学 2015-06-15 Tucker Jones , Richard S. Ellis , Matthew A. Schenker , Daniel P. Stark

The escape fraction of ionising photons from galaxies ($f_\mathrm{esc}$) is a key parameter for understanding how intergalactic hydrogen became reionised, but it remains mostly unconstrained. Measurements have been limited to the average…

星系天体物理 · 物理学 2024-12-04 Kimi C. Kreilgaard , Charlotte A. Mason , Fergus Cullen , Ryan Begley , Ross J. McLure

We present a series of high-resolution (20-2000 Msun, 0.1-4 pc) cosmological zoom-in simulations at z~6 from the Feedback In Realistic Environment (FIRE) project. These simulations cover halo masses 10^9-10^11 Msun and rest-frame…

The escape fraction of Lyman continuum photons (fesc(LyC)) is the last key unknown in our understanding of cosmic reionization. Directly estimating the escape fraction (fesc) of ionizing photons in the epoch of reionization (EoR) is…

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…

宇宙学与河外天体物理 · 物理学 2016-02-17 Mahavir Sharma , Tom Theuns , Carlos S. Frenk , Richard G. Bower , Robert A. Crain , Matthieu Schaller , Joop Schaye

We present model calculations of the reionization history of hydrogen using star formation histories, computed with a galaxy formation model which reproduces properties of local dwarf galaxies and UV luminosity functions of galaxies at…

星系天体物理 · 物理学 2025-11-12 Zewei Wu , Andrey Kravtsov , Harley Katz

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…

The part played by stars in the ionization of the intergalactic medium remains an open question. A key issue is the proportion of the stellar ionizing radiation that escapes the galaxies in which it is produced. Spectroscopy of gamma-ray…