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Related papers: LYMAN-ALPHA FOREST CORRELATIONS USING NEIGHBOR COU…

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We investigate the promise of the Ly-alpha forest for high precision cosmology in the era of the Sloan Digital Sky Survey using low order N-point statistics. We show that with the existing data one can determine the amplitude, slope and…

Astrophysics · Physics 2009-11-07 R. Mandelbaum , P. McDonald , U. Seljak , R. Cen

We present results on the evolution and clustering of Ly-alpha lines at low z. The sample contains 1298 Ly-alpha lines from 165 quasar spectra mined from the archives of the HST/FOS. Our sample extends to z=1.7, slightly higher than the…

Astrophysics · Physics 2009-11-07 Adam Dobrzycki , Jill Bechtold , Jennifer Scott , Miwa Morita

Inhomogeneous reionization enhances the 1D Lyman-$\alpha$ forest power spectrum on large scales at redshifts $z\geq4$. This is due to coherent fluctuations in the ionized hydrogen fraction that arise from large-scale variations in the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Margherita Molaro , Vid Iršič , James S. Bolton , Maggie Lieu , Laura C. Keating , Ewald Puchwein , Martin G. Haehnelt , Matteo Viel

We compute the 3D cross-correlation between the absorption of the $z\sim 2.3$ Lyman-alpha forest measured by the COSMOS Lyman-Alpha Mapping And Tomography Observations (CLAMATO) survey, and 1642 foreground galaxies with spectroscopic…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Benjamin Zhang , Khee-Gan Lee , Andrei Cuceu , Andreu Font-Ribera , Rieko Momose

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 examine the light-cone effect on the two-point correlation functions using numerical simulations for the first time. Specifically, we generate several sets of dark matter particle distributions on the light-cone up to z=0.4 and z=2 over…

Astrophysics · Physics 2009-10-31 Takashi Hamana , Stephane Colombi , Yasushi Suto

(abridged) We present an effective implementation of analytical calculations of the Lyalpha opacity distribution of the Intergalactic Medium (IGM) along multiple lines of sight (LOS) to distant quasars in a cosmological setting. This method…

Astrophysics · Physics 2009-11-06 M. Viel , S. Matarrese , H. J. Mo , M. G. Haehnelt , Tom Theuns

We present a new algorithm to rapidly compute the two-point (2PCF), three-point (3PCF) and n-point (n-PCF) correlation functions in roughly O(N log N) time for N particles, instead of O(N^n) as required by brute force approaches. The…

Astrophysics · Physics 2007-05-23 Lucy Liuxuan Zhang , Ue-Li Pen

We present a stable procedure for defining and measuring the two point angular autocorrelation function, w, of faint (25 < V < 29), barely resolved and unresolved sources in the HST GOODS and UDF datasets. We construct catalogs that include…

Astrophysics · Physics 2015-05-13 Eric Morganson , Roger Blandford

The properties of the Lyman-$\alpha$ absorptions observed in the spectra of QSOs are reviewed: the distribution of column densities and Doppler widths, the redshift evolution, the ``inverse effect'', the clustering. By interpreting the…

Astrophysics · Physics 2007-05-23 S. Cristiani

Estimates of the metagalactic hydrogen ionization rate from the Lyman-alpha forest opacity in QSO absorption spectra depend on the complex density distribution of neutral hydrogen along the line-of-sight. We use a large suite of high…

Astrophysics · Physics 2009-11-10 James S. Bolton , Martin G. Haehnelt , Matteo Viel , Volker Springel

The Ly$\alpha$ forest provides one of the best means of mapping large-scale structure at high redshift, including our tightest constraint on the distance-redshift relation before cosmic noon. We describe how the large-scale correlations in…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-02 Shi-Fan Chen , Zvonimir Vlah , Martin White

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

Absorption between the rest-frame wavelengths of 973 and 1026 Angstroms in quasar spectra arises from two sources (apart from occasional metals): one is due to Lyman-alpha (Lya) absorption by materials at a low redshift, and the other from…

Astrophysics · Physics 2009-11-07 Mark Dijkstra , Adam Lidz , Lam Hui

We determine the product of the expansion rate and angular-diameter distance at redshift $z=2.3$ from the anisotropy of Lyman-$\alpha$ (Ly$\alpha$) forest correlations measured by the Sloan Digital Sky Survey (SDSS). Our result is the most…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Andrei Cuceu , Andreu Font-Ribera , Seshadri Nadathur , Benjamin Joachimi , Paul Martini

Lyman-alpha forest lines in QSO spectra have typical widths of 20-50 km/s. Low column density absorbers in cosmological simulations are large, diffuse structures, and the Hubble flow across the spatially extended absorber is usually the…

Astrophysics · Physics 2007-05-23 David H. Weinberg , Lars Hernquist , Neal Katz , Rupert Croft , Jordi Miralda-Escudé

We propose a new method of analysis for the \lya forest, namely to measure the 1-point and 2-point joint probability distribution of the transmitted flux. The results for a sample of seven observed quasars and from two simulations of…

Measuring the two-point correlation function of the galaxies in the Universe gives access to the underlying dark matter distribution, which is related to cosmological parameters and to the physics of the primordial Universe. The estimation…

We present new methods to minimize the systematic and random errors for measuring the transmission power spectrum from the Lyman-alpha forest. Sources of systematic errors explored include metal line contamination and continuum-fitting. We…

Astrophysics · Physics 2009-10-31 Lam Hui , Scott Burles , Uros Seljak , Robert E. Rutledge , Eugene Magnier , David Tytler

We introduce methods which allow observed galaxy clustering to be used together with observed luminosity or stellar mass functions to constrain the physics of galaxy formation. We show how the projected two-point correlation function of…

Astrophysics of Galaxies · Physics 2016-03-02 Marcel P. van Daalen , Bruno M. B. Henriques , Raul E. Angulo , Simon D. M. White