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Related papers: Voids in Ly{\alpha} Forest Tomographic Maps

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We outline the physical picture of the high-redshift Ly-alpha forest that has emerged from cosmological simulations, describe statistical characteristics of the forest that can be used to test theories of structure formation, present a…

The aim of this study is to distinguish genuine cosmic voids, found in a galaxy catalog by the void finder ZOBOV-VIDE, from under-dense regions in a Poisson distribution of objects. For this purpose, we perform two multivariate analyses…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-14 M. -C Cousinou , A. Pisani , A. Tilquin , N. Hamaus , A. -J Hawken , S. Escoffier

We present a statistical analysis of voids in the 2dF galaxy redshift survey (2dFGRS). In order to detect the voids, we have developed two robust algorithms. We define voids as non-overlapping maximal spheres empty of halos or galaxies with…

In this Letter we explore a version of the test of cosmological geometry proposed by Alcock and Paczynski (1979), using observations of the Lyman-alpha forest in the spectra of close quasar pairs. By comparing the correlations in absorption…

Astrophysics · Physics 2009-10-30 Lam Hui , Albert Stebbins , Scott Burles

We investigate the properties of one--dimensional flux ``voids'' (connected regions in the flux distribution above the mean flux level) by comparing hydrodynamical simulations of large cosmological volumes with a set of observed…

Astrophysics · Physics 2009-11-13 Matteo Viel , Joerg M. Colberg , Tae-Sun Kim

Cosmic voids, the less dense patches of the Universe, are promising laboratories to extract cosmological information. Thanks to their unique low density character, voids are extremely sensitive to diffuse components such as neutrinos and…

The hydrogen Ly$\alpha$ forest is an important probe of the $z>2$ Universe that is otherwise challenging to observe with galaxy redshift surveys, but this technique has traditionally been limited to 1D studies in front of bright quasars.…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Khee-Gan Lee

We have conducted pointed redshift surveys for galaxies in the direction of bright AGN whose HST far-UV spectra contain nearby (cz <~ 30,000 kms), low column density (12.5 <= log N_{HI} (cm s^{-2}) <= 14.5) Ly-alpha forest absorption…

Astrophysics · Physics 2009-11-07 Kevin M. McLin , John T. Stocke , R. J. Weymann , Steven V. Penton , J. Micheal Shull

Cosmic voids are becoming key players in testing the physics of our Universe. Here we concentrate on the abundances and the dynamics of voids as these are among the best candidates to provide information on cosmological parameters. Cai,…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-31 Nelson Padilla , Dante Paz , Marcelo Lares , Laura Ceccarelli , Diego Garcia Lambas , Yan-Chuan Cai , Baojiu Li

Cosmic voids provide a powerful probe of the origin and evolution of structures in the Universe because their dynamics can remain near-linear to the present day. As a result they have the potential to connect large scale structure at late…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-26 Stephen Stopyra , Hiranya V. Peiris , Andrew Pontzen

We study the formation and evolution of voids in the dark matter distribution using various simulations of the popular $\Lambda$ Cold Dark Matter cosmogony. We identify voids by requiring them to be regions of space with a mean overdensity…

Astrophysics · Physics 2009-11-10 Joerg M. Colberg , Ravi K. Sheth , Antonaldo Diaferio , Liang Gao , Naoki Yoshida

We present a detailed description of our void finding algorithm which is an extension of the prescription by Hoyle and Vogeley (2002). We include a discussion of the reproducibility and robustness of the algorithm as well as the statistical…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-22 Caroline Foster , Lorne A. Nelson

Cosmic voids constitute promising cosmological laboratories. However, a full description of all the redshift-space effects that affect observational measurements is mandatory in order to obtain unbiased cosmological constraints. We make a…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-30 Carlos M. Correa , Dante J. Paz

We use an automated Voigt-profile fitting procedure to extract statistical properties of the Ly$\alpha$ forest in a numerical simulation of an $\Omega=1$, cold dark matter (CDM) universe. Our analysis method is similar to that used in most…

Astrophysics · Physics 2007-05-23 Romeel Davé , Lars Hernquist , David H. Weinberg , Neal Katz

Voids are dominant features of the cosmic web. We revisit the cosmological information content of voids and connect void properties with the parameters of the background universe. We combine analytical results with a suite of large n-body…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-24 Benjamin C. Bromley , Margaret J. Geller

We present a new method to find voids in cosmological simulations based on the tidal and the velocity shear tensors definitions of the cosmic web. We use the fractional anisotropy (FA) computed from the eigenvalues of each web scheme as a…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Sebastian Bustamante , Jaime E. Forero-Romero

Context. Cosmic voids are vast underdense regions in the cosmic web that encode crucial information about structure formation, the composition of the Universe, and its expansion history. Due to their lower density, these regions are less…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 M. D. Lepinzan , C. T. Davies , T. Castro , N. Schuster , J. Mohr , P. Monaco

The sizes and shapes of voids in a galaxy survey depend not only on the physics of structure formation, but also on the sampling density of the survey and on the algorithm used to define voids. Using an N-body simulation with a CDM power…

Astrophysics · Physics 2009-10-31 Jason D. Schmidt , Barbara S. Ryden , Adrian L. Melott

We present the first observations of foreground Lyman-$\alpha$ forest absorption from high-redshift galaxies, targeting 24 star-forming galaxies (SFGs) with $z\sim 2.3-2.8$ within a $5' \times 15'$ region of the COSMOS field. The transverse…

We study the distribution of cosmic voids and void galaxies using Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Using the VoidFinder algorithm as described by Hoyle 2002, we identify 1054 statistically significant voids in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Danny C. Pan , Michael S. Vogeley , Fiona Hoyle , Yun-Young Choi , Changbom Park