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

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The Ly$\alpha$ forest (LAF) at $z>5$ probes the thermal and reionization history of the intergalactic medium (IGM) and the nature of dark matter, but its interpretation requires comparison to cosmological hydrodynamical simulations. At…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-26 Caitlin C. Doughty , Joseph F. Hennawi , Frederick B. Davies , Zarija Lukić , Jose Oñorbe

We present a statistical analysis of Ly$\alpha$ absorption using 581 galaxies at $z=4.5$--13 observed with multiple JWST/NIRSpec spectroscopy programs, including JADES, UNCOVER, CEERS, and GO/DDT. We carefully construct composite spectra…

Astrophysics of Galaxies · Physics 2025-12-30 Hiroya Umeda , Masami Ouchi , Yuta Kageura , Yuichi Harikane , Minami Nakane , Tran Thi Thai , Kimihiko Nakajima

The Lyman-alpha forest at z >~ 5.5 shows strong scatter in the mean transmission even when smoothed over very large spatial scales, >~ 50 Mpc/h. This has been interpreted as a signature of strongly fluctuating radiation fields, or patchy…

Astrophysics · Physics 2009-11-13 Adam Lidz , S. Peng Oh , Steven R. Furlanetto

A homogeneous sample of 99 moderate resolution QSO spectra at z > 1.7 were presented in Paper I, including 39 previously unpublished spectra from the Multiple Mirror Telescope. The statistics of the Lyman alpha forest were discussed. In…

Astrophysics · Physics 2009-10-31 J. Scott , J. Bechtold , A. Dobrzycki , V. Kulkarni

During the epoch of reionization (EoR), the first generation of luminous sources in our Universe emitted ionizing photons that almost completely ionized the gas in the intergalactic medium (IGM). The growth of ionized bubbles and the…

Astrophysics of Galaxies · Physics 2025-11-26 Sambit K. Giri , Koki Kakiichi , Michele Bianco , P. Daniel Meerburg

This is the second paper in a series whose aim is to predict the power spectrum of intensity and polarized intensity from cosmic reionization fronts. After building the analytic models for intensity and polarized intensity calculations in…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Emily Koivu , Heyang Long , Yuanyuan Yang , Christopher M. Hirata

We use a semi-analytical approach to simulate absorption spectra of QSOs at high redshifts with the aim of constraining the cosmic reionization history. We consider two physically motivated and detailed reionization histories: (i) an Early…

Astrophysics · Physics 2009-11-11 S. Gallerani , T. Roy Choudhury , A. Ferrara

The fluctuations in the emission of redshifted 21cm photons from neutral inter-galactic hydrogen will provide an unprecedented probe of the reionization era. Conventional wisdom assumes that this 21cm signal disappears as soon as…

Astrophysics · Physics 2015-05-13 Stuart Wyithe , Abraham Loeb

The effective optical depth in the Ly-alpha forest region of 1061 low-resolution QSO spectra drawn from the SDSS database decreases with decreasing redshift over the range 2.5 < z < 4. Although the evolution is relatively smooth, tau_eff ~…

We use numerical simulations to study the effects of the patchiness of a partly reionized intergalactic medium (IGM) on the observability of Ly-alpha emitters (LAEs) at high redshifts (z ~ 6). We present a new model that divides the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Hannes Jensen , Peter Laursen , Garrelt Mellema , Ilian T. Iliev , Jesper Sommer-Larsen , Paul R. Shapiro

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

We present a Bayesian inference on the neutral hydrogen fraction of the intergalactic medium (IGM), $x_{\textrm{HI}}$, at $z \sim$ 6-8 using the properties of Lyman break galaxies during the Epoch of Reionization. We use large samples of…

We examine the evolution of the IGM Ly-alpha optical depth distribution using the transmitted flux probability distribution function (PDF) in a sample of 63 QSOs spanning absorption redshifts 1.7 < z < 5.8. The data are compared to two…

Astrophysics · Physics 2011-02-11 George D. Becker , Michael Rauch , Wallace L. W. Sargent

Arguably the best hope of understanding the tail end of the reionization of the intergalactic medium (IGM) at redshift z > 6 is through the detection and characterization of the Gunn-Peterson (GP) damping wing absorption of the IGM in…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-25 Roban Hultman Kramer , Zoltan Haiman

We present a new method to study the contribution of faint sources to the UV background using the 1D correlation of metal absorbers with the intergalactic medium (IGM) transmission in a Quasi Stellar Object (QSO) sightline. We take…

Astrophysics of Galaxies · Physics 2018-11-07 Romain A. Meyer , Sarah E. I. Bosman , Koki Kakiichi , Richard S. Ellis

QSO near-zones are an important probe of the the ionization state of the IGM at z ~ 6-7, at the end of reionization. We present here high-resolution cosmological 3D radiative transfer simulations of QSO environments for a wide range of host…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Laura C. Keating , Martin G. Haehnelt , Sebastiano Cantalupo , Ewald Puchwein

Recent JWST observations at $z > 6$ may imply galactic ionizing photon production above prior expectations. Under observationally motivated assumptions about escape fractions, these suggest a $z \sim 8-9$ end to reionization, in tension…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-15 Christopher Cain , Garett Lopez , Anson D'Aloisio , Julian B. Munoz , Rolf A. Jansen , Rogier A. Windhorst , Nakul Gangolli

We perform an analysis of the cosmic reionization in the standard cold dark matter (CDM) paradigm and in alternative dark matter scenarios. Building upon the work of Corasaniti et al. (2017), we predict the reionization history for CDM, for…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 Isabella P. Carucci , Pier-Stefano Corasaniti

We present constraints on the reionization optical depth, $\tau$, obtained using several independent methods. First, we perform a non-parametric reconstruction of the reionization history, using Lyman-$\alpha$ constraints on the evolution…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-29 Willem Elbers

We use high quality echelle spectra of 24 QSOs to provide a calibrated measurement of the total amount of Lyman-alpha forest absorption (DA) over the redshift range 2.2 < z < 3.2. Our measurement of DA excludes absorption from metal lines…