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Related papers: Probing the Intergalactic Medium with Ly$\mathrm{\…

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The high-redshift 21-cm signal of neutral hydrogen is expected to be observed within the next decade and will reveal epochs of cosmic evolution that have been previously inaccessible. Due to the lack of observations, many of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 Aviad Cohen , Anastasia Fialkov , Rennan Barkana

We investigate Lyman-alpha (Ly$\alpha$) transmission spikes at $5.2 < z < 6.8$ using synthetic quasar spectra from the ``Cosmic Reionization On Computers" simulations. We focus on understanding the relationship between these spikes and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Hanjue Zhu , Nickolay Gnedin , Camille Avestruz

Lyman-$\alpha$ (Ly$\alpha$) emitting galaxies are powerful tools to probe the late stages of cosmic reionization. The observed sudden drop in Ly$\alpha$ fraction at $z>6$ is often interpreted as a sign of reionization, since the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Sultan Hassan , Max Gronke

A crucial physical quantity in determining the 21-cm signal during cosmic dawn is the inhomogeneous background of Ly$\alpha$ photons originating from the first galaxies. As these photons travel through the intergalactic medium, their…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Jordan Flitter , Julian B. Muñoz , Andrei Mesinger

(abridged) We present an effective implementation of analytical calculations of the Lyalpha opacity distribution of the Intergalactic Medium (IGM) along multiple lines of sight (LOS) to distant quasars in a cosmological setting. This method…

Astrophysics · Physics 2009-11-06 M. Viel , S. Matarrese , H. J. Mo , M. G. Haehnelt , Tom Theuns

The large cross-section of the Lyman alpha (Lya) line makes it a sensitive probe of the ionization state of the intergalactic medium (IGM). Here we present the most complete study to date of the IGM Lya opacity, and its application to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Andrei Mesinger , Aycin Aykutalp , Eros Vanzella , Laura Pentericci , Andrea Ferrara , Mark Dijkstra

The decline in abundance of Lyman-$\alpha$ (Ly$\alpha$) emitting galaxies at $z \gtrsim 6$ is a powerful and commonly used probe to constrain the progress of cosmic reionization. We use the CoDaII simulation, which is a radiation…

We present a new perturbative approach to "constrained Ly$\alpha$ radiative transfer'" (RT) through the circum- and inter-galactic medium (CGM and IGM). We constrain the HI content and kinematics of the CGM and IGM in a physically motivated…

Astrophysics of Galaxies · Physics 2018-08-22 Koki Kakiichi , Mark Dijkstra

We study the intergalactic transmission of radiation in the vicinity of the Ly{\alpha} wavelength. Simulating sightlines through the intergalactic medium (IGM) in detailed cosmological hydrosimulations, the impact of the IGM on the shape of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Peter Laursen , Jesper Sommer-Larsen , Alexei O. Razoumov

Numerical hydrodynamical simulations have proven a successful means of reproducing many of the statistical properties of the LyA forest as measured in high redshift (z > 4) quasar spectra. The source of ionization of the Intergalactic…

Astrophysics · Physics 2008-11-26 Avery Meiksin , Martin White

We calculate the impact of the intergalactic medium (IGM) on the observed Lyman alpha lines (hereafter Lya) emitted by galaxies in an ionised IGM at z>4. Our model accounts for gas clumping in the IGM and for the fact that high-redshift…

Astrophysics · Physics 2008-11-26 Mark Dijkstra , Adam Lidz , Stuart Wyithe

We explore how the characteristics of the cross-correlation functions between the 21cm emission from the spin-flip transition of neutral hydrogen (HI) and early Lyman-$\alpha$ (Ly$\alpha$) radiation emitting galaxies (Ly$\alpha$ emitters,…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 Anne Hutter , Caroline Heneka , Pratika Dayal , Stefan Gottlöber , Andrei Mesinger , Maxime Trebitsch , Gustavo Yepes

The observed scatter in intergalactic Lyman-$\alpha$ opacity at $z \lesssim 6$ requires large-scale fluctuations in the neutral fraction of the intergalactic medium (IGM) after the expected end of reionization. Post-reionization models that…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 George D. Becker , Frederick B. Davies , Steven R. Furlanetto , Matthew A. Malkan , Elisa Boera , Craig Douglass

We present a new flexible Bayesian framework for directly inferring the fraction of neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR, z~6-10) from detections and non-detections of Lyman Alpha…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Charlotte A. Mason , Tommaso Treu , Mark Dijkstra , Andrei Mesinger , Michele Trenti , Laura Pentericci , Stephane de Barros , Eros Vanzella

Using the CoDa II simulation, we study the Ly$\alpha$ transmissivity of the intergalactic medium (IGM) during reionization. At $z>6$, a typical galaxy without an active galactic nucleus fails to form a proximity zone around itself due to…

Cross-correlating 21cm with known cosmic signals will be invaluable proof of the cosmic origin of the first 21cm detections. As some of the widest fields available, comprising thousands of sources with reasonably known redshifts,…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Caroline Heneka , Andrei Mesinger

A unified description is provided for the 21cm signatures arising from minihaloes against a bright background radio source and against the Cosmic Microwave Background (CMB), within the context of a dynamical collapsing cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-14 Avery Meiksin

We explore the possibility of detecting HI 21cm absorption by the neutral intergalactic medium (IGM) toward very high redshift radio sources. The epoch considered is between the time when the first ionizing sources form and when the bulk of…

Astrophysics · Physics 2016-08-30 C. Carilli , N. Y. Gnedin , F. Owen

Absorption or emission against the cosmic microwave background radiation (CMB) may be observed in the redshifted 21cm line if the spin temperature of the neutral intergalactic medium prior to reionization differs from the CMB temperature.…

Astrophysics · Physics 2009-12-10 Tiziana Di Matteo , Rosalba Perna , Tom Abel , Martin J. Rees

Ly$\alpha$ emission from galaxies can be utilized to characterize the ionization state in the intergalactic medium (IGM). We report our search for Ly$\alpha$ emission at $z>7$ using a comprehensive Keck/MOSFIRE near-infrared spectroscopic…