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Related papers: Studying the Lyman-$\alpha$ optical depth fluctuat…

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We conduct an analysis of the Planck 2015 data that is complete in reionization observables from the large angle polarization $E$-mode spectrum in the redshift range $6 < z < 30$. Based on 5 principal components, all of which are…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 Chen He Heinrich , V Miranda , Wayne Hu

While limited to low spatial resolution, the next generation low-frequency radio interferometers that target 21 cm observations during the era of reionization and prior will have instantaneous fields-of-view that are many tens of square…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 M. G. Santos , L. Ferramacho , M. B. Silva , A. Amblard , A. Cooray

We use large simulations of Lyman-Alpha Emitters with different fractions of ionized intergalactic medium to quantify the clustering of Ly$\alpha$ emitters as measured by the Void Probability function (VPF), and how it evolves under…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-24 Lucia A. Perez , Sangeeta Malhotra , James E. Rhoads , Isak G. B. Wold

Recently, the Lyman-$\alpha$ (Ly$\alpha$) forest flux auto-correlation function has been shown to be sensitive to the mean free path of hydrogen-ionizing photons, $\lambda_{\text{mfp}}$, for simulations at $z \geq 5.4$. Measuring…

We study the evolution with redshift of the number density of Ly$\alpha$ clouds in a CDM model using numerical simulations including photo-ionization and cooling of the baryonic component. The photo-ionizing flux is consistently taken as…

Astrophysics · Physics 2019-08-17 Jan P. Mücket , Patrick Petitjean , Ronald E. Kates , Rüdiger Riediger

The relation between the Lyman-$\alpha$ effective optical depth of quasar sightlines ($\tau_\mathrm{los}$) and the distribution of galaxies around them is an emerging probe of the connection between the first collapsed structures and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-09 Enrico Garaldi , Verena Bellscheidt , A. Smith , R. Kannan

We present a new analytical model for the attenuation to Epoch of Reionization (EoR) galaxies by proximate neutral hydrogen gas. Many galaxy spectra in the EoR taken by JWST have shown a flux deficit at wavelengths just redward of the Lyman…

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 investigate Lyman-$\alpha$ transmission spikes at $z > 5$ in synthetic quasar spectra, and discuss their connection to the properties of the intergalactic medium and their ability to constrain reionization models. We use state-of-the-art…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-08 Enrico Garaldi , Nickolay Gnedin , Piero Madau

We investigate the thermal and ionization history of Lyman alpha clouds photoionized by a time--dependent UV background, including non equilibrium effects. The results show that it is possible to obtain temperatures as low as T~15000 K (or,…

Astrophysics · Physics 2015-06-24 A. Ferrara , E. Giallongo

The physical conditions of the intergalactic medium (IGM) during the final stages of cosmic reionization ($z\sim5.0-6.0$) are not yet fully understood. Recent reports of unexpectedly large-scale ($\ge 150 h^{-1}\mathrm{cMpc}$) correlation…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Barun Maity , Frederick B. Davies , Benedetta Spina , Sarah E. I. Bosman

Observations of high-redshift Ly-alpha sources are a major tool for studying the high-redshift Universe. We discuss the effect of the reionizing intergalactic medium on the observability of Ly-alpha sources based on large simulations of…

Astrophysics · Physics 2009-11-13 Ilian T. Iliev , Paul R. Shapiro , Patrick McDonald , Garrelt Mellema , Ue-Li Pen

We describe the initial results of a deep long-slit emission line search for redshifted (2.7<z<4.1) Lyman-alpha. These observations are used to constrain the fluorescent Ly-alpha emission from the population of clouds whose absorption…

Astrophysics · Physics 2015-06-24 Andrew J. Bunker , Francine R. Marleau , James R. Graham

We present here 21 cm predictions from high dynamic range simulations for a range of reionization histories that have been tested against available Lyman-alpha and CMB data. We assess the observability of the predicted spatial 21 cm…

Astrophysics of Galaxies · Physics 2016-09-13 Girish Kulkarni , Tirthankar Roy Choudhury , Ewald Puchwein , Martin G. Haehnelt

Large fluctuations in the electron column density can occur during the reionization process. We investigate the possibility of deriving the electron density fluctuations through detailed mapping of the redshifted 21-cm emission from the…

Astrophysics · Physics 2009-11-11 Gilbert Holder , Ilian T. Iliev , Garrelt Mellema

We study the reionization history of the Universe in cosmological models with non-Gaussian density fluctuations, taking them to have a renormalized $\chi^2$ probability distribution function parametrized by the number of degrees of freedom,…

Astrophysics · Physics 2009-11-11 Pedro P. Avelino , Andrew R. Liddle

We present a new investigation of the thermal history of the intergalactic medium (IGM) during and after reionization using the Lyman-$\alpha$ forest flux power spectrum at $4.0\lesssim z\lesssim5.2$. Using a sample of 15 high-resolution…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Elisa Boera , George D. Becker , James S. Bolton , Fahad Nasir

We model the high redshift (z > 5) Lyman-$\alpha$ emitting (LAE) galaxy population using the empirical rest-frame equivalent width distribution. We calibrate to the observed luminosity function and angular correlation function at z = 5.7 as…

Astrophysics of Galaxies · Physics 2019-02-19 Lewis H. Weinberger , Martin G. Haehnelt , Girish Kulkarni

Lyman alpha (Lya) emission lines should be attenuated in a neutral intergalactic medium (IGM). Therefore the visibility of Lya emitters at high redshifts can serve as a valuable probe of reionization at about the 50% level. We present an…

The conditions within the ionization front of a quasar during reionization (T ~ 30,000 K, neutral hydrogen fraction ~ 0.5) are ideal for producing Lyman-alpha emission via collisional excitation of hydrogen atoms. Observations of this…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Frederick B. Davies , Steven R. Furlanetto , Matthew McQuinn