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We investigate the relationship between the Lyman-alpha (Lya) forest transmission in the intergalactic medium (IGM) and the environmental density of galaxies, focusing on its implications for the measurement of ionizing radiation escape…

Astrophysics of Galaxies · Physics 2025-04-24 C. Scarlata , W. Hu , M. J. Hayes , S. Taamoli , A. A. Khostovan , C. M. Casey , A. L. Faisst , J. S. Kartaltepe , Y. Lin , M. Salvato , M. Rafelski

We have obtained spectroscopy of Q 1343+266 AB, a pair of quasars at redshift z = 2.03 with a projected separation of 9.5 arcseconds. This system is well-suited for probing the Ly-alpha forest, since the two component spectra show several…

Astrophysics · Physics 2009-10-22 Jill Bechtold , Arlin P. S. Crotts , Robert C. Duncan , Yihu Fang

We examine the Ly-alpha absorber population at z<0.3 detected in spectra of the QSOs PG0953+415 and H1821+643 taken with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. We compare their statistical properties to…

Astrophysics · Physics 2009-11-06 Romeel Davé , Todd M. Tripp

We present the one-dimensional Lyman-$\alpha$ forest power spectrum measurement derived from the data release 1 (DR1) of the Dark Energy Spectroscopic Instrument (DESI). The measurement of the Lyman-$\alpha$ forest power spectrum along the…

The highly anisotropic nature of the Lyman-alpha (Ly$\alpha$) forest data introduces a complex survey window function that complicates the measurement of the three-dimensional power spectrum ($P_{\mathrm{3D}}$). In this paper, we present…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-19 N. G. Karaçaylı , C. M. Hirata

We suggest an adaptive sampling rule for obtaining information from noisy signals using wavelet methods. The technique involves increasing the sampling rate when relatively high-frequency terms are incorporated into the wavelet estimator,…

Statistics Theory · Mathematics 2007-06-13 Peter Hall , Spiridon Penev

We study the clustering of matter in the intergalactic medium from the Lyman-alpha forests seen in the spectra of pairs or groups of z ~ 2 quasars observed with FORS2 and UVES at the VLT-UT2 Kueyen ESO telescope. The sample consists of five…

Astrophysics · Physics 2009-11-07 E. Rollinde , P. Petitjean , C. Pichon , S. Colombi , B. Aracil , V. D'Odorico , M. G. Haehnelt

The Lyman-$\alpha$ forest refers to the series of absorption features observed in the spectra of distant quasars that are produced by neutral hydrogen in the intergalactic medium. Observed over a wide range of redshifts with both ground-…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Jonás Chaves-Montero

We combine a cosmological reionization simulation with box size of 100Mpc/h on a side and a Monte Carlo Lyman-alpha (Lya) radiative transfer code to model Lyman Alpha Emitters (LAEs) at z~5.7. The model introduces Lya radiative transfer as…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Zheng Zheng , Renyue Cen , Hy Trac , Jordi Miralda-Escude

Correlations in the Lyman-$\alpha$ (Ly$\alpha$) forest, both as a function of line of sight separation (1D) and 3D separation, provide a unique window to the distribution of matter at redshifts not accessible by current galaxy surveys.…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-07 Martine Lokken , Andreu Font-Ribera , Patrick McDonald

In this paper we critically examine predictions of the Lya forest within the standard cold dark matter (SCDM) model, paying particular attention to the low end of the column-density distribution. We show in particular that the width of…

Astrophysics · Physics 2009-10-30 Greg L. Bryan , Marie Machacek , Peter Anninos , Michael L. Norman

We measure the matter power spectrum from the Lyman-alpha forest of 31 quasar spectra spanning the redshift range of 1.6-3.6. The optical depth, $\tau$, for absorption of the intergalactic medium is obtained from the flux using the…

Astrophysics · Physics 2009-11-11 S. Zaroubi , M. Viel , A. Nusser , M. Haehnelt , T. -S. Kim

We present the analysis of a sample of the Ly-$\alpha$ forest spectra of 152 quasars taken with the HST FOS. The Ly-$\alpha$ lines show little evolution at $0<z<1.7$. We see a difference between the evolution indices for weak and strong…

Astrophysics · Physics 2007-05-23 Adam Dobrzycki , Jill Bechtold

In gravitational instability models, \lya absorption arises from a continuous fluctuating medium, so that spectra provide a non-linear one-dimensional ``map'' of the underlying density field. We characterise this continuous absorption using…

Astrophysics · Physics 2007-05-23 Rupert A. C. Croft , David H. Weinberg , Lars Hernquist , Neal Katz

A convincing physical picture for the Lyman-alpha forest has emerged from simulations and related semi-analytic studies of structure formation models. Observations can be be used in the context of this picture to study cosmology using the…

Astrophysics · Physics 2007-05-23 Rupert Croft , David Weinberg , Neal Katz , Lars Hernquist

In the realm of signal processing, frequency and spectrum detection are fundamental tasks that can be computationally intensive. This project leverages the power of FPGAs to perform wavelet analysis on an input signal. The goal is to detect…

Hardware Architecture · Computer Science 2024-12-31 Caleb Hill , Darshika G. Perera

The Lyman-$\alpha$ (Ly$\alpha$) three-dimensional correlation functions have been widely used to perform cosmological inference using the baryon acoustic oscillation (BAO) scale. While the traditional inference approach employs a data…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-15 Francesca Gerardi , Andrei Cuceu , Benjamin Joachimi , Seshadri Nadathur , Andreu Font-Ribera

Properties of $\sim$ 6 000 Ly-$\alpha$ absorbers observed in 19 high resolution spectra of QSOs are investigated using the model of formation and evolution of DM structure elements based on the Zel'dovich theory. This model asserts that…

Astrophysics · Physics 2009-11-11 M. Demianski , A. G. Doroshkevich , V. I. Turchaninov

We measure the 1D Ly$\,\alpha$ power spectrum $P_\mathrm{1D}$ from Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ), The Spectral Quasar Absorption Database (SQUAD) and XQ-100 quasars using the optimal quadratic…

We quantify the impact of massive neutrinos on the statistics of low density regions in the intergalactic medium (IGM) as probed by the Lyman-alpha forest at redshifts z=2.2--4. Based on mock but realistic quasar (QSO) spectra extracted…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 Francisco Villaescusa-Navarro , Mark Vogelsberger , Matteo Viel , Abraham Loeb