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Related papers: Mapping the Cosmic Web with Ly-alpha Emission

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We simulate the flux emitted from galaxy halos in order to quantify the brightness of the circumgalactic medium (CGM). We use dedicated zoom-in cosmological simulations with the hydrodynamical Adaptive Mesh Refinement code RAMSES, which are…

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

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

Ly$\alpha$ intensity mapping is emerging as a new probe of faint galaxies consisting the cosmic web that elude traditional surveys. However, the resonant nature of Ly$\alpha$ radiative transfer complicates the interpretation of observed…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Hyunbae Park , Hyunmi Song , Chris Byrohl , Aaron Smith , Yajima Hidenobu , Zarija Lukić

The fraction of galaxies with strong Ly$\alpha$ emission has been observed to decrease rapidly with redshift at $z \ge 6$, after a gradual increase at $z< 6$. This has been interpreted as a hint of the reionization of the intergalactic…

Astrophysics of Galaxies · Physics 2017-04-14 Raphael Sadoun , Zheng Zheng , Jordi Miralda-Escudé

With the Multi Unit Spectroscopic Explorer (MUSE), it is now possible to detect spatially extended Lyman alpha emission from individual faint (M_UV ~ -18) galaxies at redshifts, 3 < z < 6, tracing gas out to circum-galactic scales…

Astrophysics of Galaxies · Physics 2021-01-13 Peter Mitchell , Jérémy Blaizot , Corentin Cadiou , Yohan Dubois , Thibault Garel , Joakim Rosdahl

We describe a new approach to studying the intergalactic and circumgalactic medium in the local Universe: direct detection through narrow-band imaging of ultra-low surface brightness visible-wavelength line emission. We use the…

Astrophysics of Galaxies · Physics 2019-05-29 Deborah Lokhorst , Roberto Abraham , Pieter van Dokkum , Nastasha Wijers , Joop Schaye

Lyman-$\alpha$ (Ly$\alpha$) spectra provide insights into the small-scale structure and kinematics of neutral hydrogen (HI) within galaxies as well as the ionization state of the intergalactic medium (IGM). The former defines the intrinsic…

Astrophysics of Galaxies · Physics 2020-10-21 Chris Byrohl , Max Gronke

Lyman-Alpha (Lya) photons emitted in star-forming galaxies undergo complex radiative transfer through the interstellar (ISM), circumgalactic (CGM), and intergalactic medium (IGM), imprinting characteristic signatures on their observed line…

We perform a systematic study of how the inhomogeneities in the Inter-Galactic Medium (IGM) affect the observability of Lyman Alpha Emitters (LAEs) around the Epoch of Reionization. We focus on the IGM close to the galaxies as the detailed…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-30 Akila Jeeson-Daniel , Benedetta Ciardi , Umberto Maio , Marco Pierleoni , Mark Dijkstra , Antonella Maselli

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

The discovery of giant quasar Ly$\alpha$ nebulae at $z>2$ has opened up the possibility to directly study in emission the Circumgalactic and Intergalactic Medium (CGM/IGM). However, the resonant nature of the Ly$\alpha$ line and its…

During reionization, a fraction of galactic Ly$\alpha$ emission is scattered in the intergalactic medium (IGM) and appears as a diffuse light extending megaparsecs from the source. We investigate how to probe the properties of the early…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-08 Hyunbae Park , Hyo Jeong Kim , Kyungjin Ahn , Hyunmi Song , Intae Jung , Pierre Ocvirk , Paul R. Shapiro , Taha Dawoodbhoy , Jenny G. Sorce , Ilian T. Iliev

The Palomar Cosmic Web Imager (PCWI), an integral field spectrograph designed to detect and map low surface brightness emission, has obtained imaging spectroscopic maps of Ly-alpha from the circum-QSO medium (CQM) of QSO HS1549+19 at…

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 present new simulations of Lyman-$\alpha$ (Ly$\alpha$) intensity maps that include Ly$\alpha$ radiative transfer in the intergalactic medium (IGM) and all significant sources of Ly$\alpha$ photons. The sources considered include…

Astrophysics of Galaxies · Physics 2025-08-29 Abigail E. Ambrose , Eli Visbal , Mihir Kulkarni , Matthew McQuinn

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…

We use Hubble space telescope data of 45 nearby star-forming galaxies to investigate properties of Lyman-alpha (Ly$\alpha$) halos, Ly$\alpha$ morphology, and the star-forming characteristics of galaxies. We study how the morphology of…

The intergalactic medium (IGM) prior to the epoch of reionization consists mostly of neutral hydrogen gas. Ly-alpha photons produced by early stars resonantly scatter off hydrogen atoms, causing energy exchange between the radiation field…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Antonija Oklopcic , Christopher M. Hirata

We use a cosmological hydrodynamic simulation of a cold dark matter universe to investigate theoretically the relationship between high redshift galaxies and the Lyman=alpha forest at redshift z=3. Galaxies in the simulation are surrounded…