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Related papers: Optimal 1D Ly-$\alpha$ Forest Power Spectrum Estim…

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We present a new measurement of the Ly${\alpha}$ forest power spectrum at $1.8 < z < 3.4$ using 74 Keck/HIRES and VLT/UVES high-resolution, high-S/N quasar spectra. We developed a custom pipeline to measure the power spectrum and its…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-03 Michael Walther , Joseph F. Hennawi , Hector Hiss , Jose Oñorbe , Khee-Gan Lee , Alberto Rorai , John O'Meara

The complex geometry of the Ly$\alpha$ forest data has motivated the use of various two-point statistics as alternatives to the three-dimensional power spectrum ($P_{\mathrm{3D}}$), which carries cosmological information in Fourier space.…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-05 N. G. Karaçaylı , P. L. Taylor

Interpreting observations of the Lyman-$\alpha$ forest flux power spectrum requires interpolation between a small number of expensive simulations. We present a Gaussian process emulator modelling the 1D flux power spectrum as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-17 Christian Pedersen , Andreu Font-Ribera , Keir K. Rogers , Patrick McDonald , Hiranya V. Peiris , Andrew Pontzen , Anže Slosar

(abridged) The flux power spectrum of the Lyman-alpha forest in quasar (QSO) absorption spectra is sensitive to a wide range of cosmological and astrophysical parameters and instrumental effects. Modelling the flux power spectrum in this…

Astrophysics · Physics 2015-06-24 Matteo Viel , Martin G. Haehnelt

We perform an analysis of the full shapes of Lyman-$\alpha$ (Ly$\alpha$) forest correlation functions measured from the first data release (DR1) of the Dark Energy Spectroscopic Instrument (DESI). Our analysis focuses on measuring the…

We test a method to reduce unwanted sample variance when predicting Lyman-$\alpha$ (ly$\alpha$) forest power spectra from cosmological hydrodynamical simulations. Sample variance arises due to sparse sampling of modes on large scales and…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-16 Lauren Anderson , Andrew Pontzen , Andreu Font-Ribera , Francisco Villaescusa-Navarro , Keir K. Rogers , Shy Genel

When measuring the one-dimensional power spectrum of the Ly$\alpha$ forest, it is common to measure the power spectrum in flux fluctuations red-ward of the Ly$\alpha$ emission of quasars and subtract this power from the measurements of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-13 Vid Iršič , Anže Slosar

We investigate the possibility of constraining primordial non-Gaussianity using the 3D bispectrum of Ly-alpha forest. The strength of the quadratic non-Gaussian correction to an otherwise Gaussian primordial gravitational field is assumed…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-19 Dhiraj Kumar Hazra , Tapomoy Guha Sarkar

We measure the power spectrum, P_F(k,z), of the transmitted flux in the Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital Sky Survey. This sample is almost two orders of magnitude larger than any previously…

We present methods for interpolating between the 1-D flux power spectrum of the Lyman-$\alpha$ forest, as output by cosmological hydrodynamic simulations. Interpolation is necessary for cosmological parameter estimation due to the limited…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Simeon Bird , Keir K. Rogers , Hiranya V. Peiris , Licia Verde , Andreu Font-Ribera , Andrew Pontzen

We measure the three-dimensional power spectrum (P3D) of the transmitted flux in the Lyman-a (Ly-a) forest using the complete extended Baryon Oscillation Spectroscopic Survey data release 16 (eBOSS DR16). This sample consists of 205,012…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-11 Roger de Belsunce , Oliver H. E. Philcox , Vid Irsic , Patrick McDonald , Julien Guy , Nathalie Palanque-Delabrouille

We present a novel maximum a posteriori estimator to jointly estimate band-powers and the covariance of the three-dimensional power spectrum (P3D) of Lyman-alpha forest flux fluctuations, called MAPLE. Our Wiener-filter based algorithm…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-27 Benjamin Horowitz , Roger de Belsunce , Zarija Lukic

We analyze the SDSS Ly-alpha forest P_F(k,z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-PM simulations. We account for the effect of absorbers…

We propose a new method for fitting the full-shape of the Lyman-$\alpha$ (Ly$\alpha$) forest three-dimensional (3D) correlation function in order to measure the Alcock-Paczynski (AP) effect. Our method preserves the robustness of baryon…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-25 Andrei Cuceu , Andreu Font-Ribera , Benjamin Joachimi , Seshadri Nadathur

We present an analysis of Si III absorption and its effect on the 1D Ly$\alpha$ forest power spectrum using the Sherwood-Relics hydrodynamical simulation suite. In addition to oscillations from the Ly$\alpha$--Si III cross correlation that…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Ke Ma , James S. Bolton , Vid Irsic , Prakash Gaikwad , Ewald Puchwein

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 a new cosmological analysis of the small-scale Lyman alpha forest 1D flux power spectrum (P1D) using high-resolution quasar spectra from XQ100 and KODIAQ-SQUAD, interpreted through the PRIYA emulator. PRIYA is a suite of galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-24 Ming-Feng Ho , Mahdi Qezlou , Simeon Bird , Yanhui Yang , Camille Avestruz , M. A. Fernandez , Vid Iršič

The Lyman-$\alpha$ forest is a valuable probe of dark matter models featuring a scale-dependent suppression of the power spectrum as compared to $\Lambda$CDM. In this work, we present a new estimator of the Lyman-$\alpha$ flux power…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Mathias Garny , Thomas Konstandin , Laura Sagunski , Sean Tulin

We present a method to recover the shape and amplitude of the power spectrum of mass fluctuations, P(k), from observations of the high redshift \lya forest. The method is motivated by the physical picture of the \lya forest that has emerged…

Astrophysics · Physics 2009-10-30 Rupert A. C. Croft , David H. Weinberg , Neal Katz , Lars Hernquist