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Related papers: Time-Dependent Behavior of Lyman$\alpha$ Photon Tr…

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The standard $\rm \Lambda$CDM cosmological model predicts that a large amount of diffuse neutral hydrogen distributes in cosmic filaments, which could be mapped through Lyman-alpha (Ly$\alpha$) emission observations. We use the…

Astrophysics of Galaxies · Physics 2025-08-29 Yizhou Liu , Liang Gao , Shihong Liao , Kai Zhu

We analyze the Ly alpha forest properties of a sample of 15 high redshift quasars lying between z = 4.42 and z = 5.75, using high signal-to-noise spectra obtained with ESI on the Keck II 10 m telescope. The distribution of transmissions in…

Astrophysics · Physics 2009-11-07 Antoinette Songaila , Lennox L. Cowie

Radiation pressure from Lyman-$\alpha$ (Ly$\alpha$) scattering is a potentially dominant form of early stellar feedback, capable of injecting up to $\sim 100 \, \times$ more momentum into the interstellar medium (ISM) than UV continuum…

Astrophysics of Galaxies · Physics 2025-01-10 Olof Nebrin , Aaron Smith , Kevin Lorinc , Johan Hörnquist , Åsa Larson , Garrelt Mellema , Sambit K. Giri

We present results from the LymAn Continuum Escape Survey (LACES), a Hubble Space Telescope (HST) program designed to characterize the ionizing radiation emerging from a sample of Lyman alpha emitting galaxies at redshift $z\simeq 3.1$. As…

The usefulness of H I Lyman-alpha photons for characterizing star formation in the distant universe is limited by our understanding of the astrophysical processes that regulate their escape from galaxies. These processes can only be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 A. Wofford , C. Leitherer , J. Salzer

The fraction of ionizing photons that escape high-redshift galaxies sensitively determines whether galaxies reionized the early universe. However, this escape fraction cannot be measured from high-redshift galaxies because the opacity of…

Astrophysics of Galaxies · Physics 2018-08-08 J. Chisholm , S. Gazagnes , D. Schaerer , A. Verhamme , J. R. Rigby , M. Bayliss , K. Sharon , M. Gladders , H. Dahle

We investigate the relation between the turbulent Mach number (\mach) and the escape fraction of Lyman continuum photons ($f_{\rm esc}$) in high-redshift galaxies. Approximating the turbulence as isothermal and isotropic, we show that the…

Astrophysics of Galaxies · Physics 2016-11-23 Mohammadtaher Safarzadeh , Evan Scannapieco

A population of early star-forming galaxies is the leading candidate for the re-ionization of the universe. It is still unclear what conditions and physical processes would enable a significant fraction of the ionizing photons to escape…

Astrophysics of Galaxies · Physics 2015-09-16 Rachael Alexandroff , Timothy Heckman , Sanchayeeta Borthakur , Roderik Overzier , Claus Leitherer

Star forming galaxies have long been considered the dominant sources of the cosmic ultraviolet background radiation at early epochs. However, observing and characterizing the galaxy population with significant ionizing emission has proven…

Astrophysics of Galaxies · Physics 2017-04-12 J. Japelj , E. Vanzella , F. Fontanot , S. Cristiani , G. B. Caminha , P. Tozzi , I. Balestra , P. Rosati , M. Meneghetti

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…

Astrophysics of Galaxies · Physics 2023-06-28 Jonas Bremer , Pratika Dayal

Galactic outflows are critical to our understanding of galaxy formation and evolution. However the details of the underlying feedback process remain unclear. We compare Ly$\alpha$ observations of the circumgalactic medium (CGM) of Lyman…

Astrophysics of Galaxies · Physics 2019-01-23 Andrew S. Chung , Mark Dijkstra , Benedetta Ciardi , Koki Kakiichi , Thorsten Naab

We perform Lyman-$\alpha$ (Ly$\alpha$) Monte-Carlo radiative transfer calculations on a suite of $2500$ models of multiphase, outflowing media, which are characterized by $14$ parameters. We focus on the Ly$\alpha$ spectra emerging from…

Astrophysics of Galaxies · Physics 2016-07-20 Max Gronke , Mark Dijkstra

We model the requirements on observational data that would allow an accurate determination of the degree of association between Lyman alpha absorbers and peaks in the redshift distribution of galaxies (large-scale structures like clusters…

Astrophysics · Physics 2009-10-28 Vicki L. Sarajedini , Richard F. Green , Buell T. Jannuzi

We combine a high-resolution hydro-simulation of the LambdaCDM cosmology with two radiative transfer schemes (for continuum and line radiation) to predict the properties, spectra and spatial distribution of fluorescent Ly-alpha emission at…

Astrophysics · Physics 2009-11-10 Sebastiano Cantalupo , Cristiano Porciani , Simon J. Lilly , Francesco Miniati

A three-dimensional Monte Carlo Ly-alpha radiative transfer (RT) code, named LaRT, is developed to study the Ly-alpha RT and the Wouthuysen-Field (WF) effect. Using the code, we calculate the line profile of Ly-alpha radiation within the…

Astrophysics of Galaxies · Physics 2020-09-09 Kwang-Il Seon , Chang-Goo Kim

We present the first comprehensive evolutionary analysis of the rest-frame UV spectroscopic properties of star-forming galaxies at z ~ 2-4. We match samples at different redshifts in UV luminosity and stellar mass, and perform systematic…

We present a model for the Lyman-alpha absorbers that treats all objects (from the low-density forest clouds to the dense damped systems) in a unified description. This approach is consistent with an earlier model of galaxies (luminosity…

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

We present new results on the Ly-alpha emission-line kinematics of 18 z~2-3 star-forming galaxies with multiple-peaked Ly-alpha profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Kristin R. Kulas , Alice E. Shapley , Juna A. Kollmeier , Zheng Zheng , Charles C. Steidel , Kevin N. Hainline

Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with WFC3/IR onboard the Hubble Space Telescope, we present new evidence for a reversal in the redshift-dependent fraction of star forming…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. A. Schenker , D. P Stark , R. S. Ellis , B. E. Robertson , J. S. Dunlop , R. J. McLure , J. -P. Kneib , J. Richard

We discuss the evolution of the ratio in number of recombinations due to 2s two photon escape and due to the escape of Lyman-$\alpha$ photons from the resonance during the epoch of cosmological recombination, within the width of the last…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-21 J. A. Rubino-Martin , R. A. Sunyaev