English
Related papers

Related papers: Cosmology with the Lyman-alpha Forest

200 papers

We present a theoretical estimate for a new observable: the cross-correlation between the Lyman-alpha flux fluctuations in quasar (QSO) spectra and the convergence of the cosmic microwave background (CMB) as measured along the same…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Alberto Vallinotto , Sudeep Das , David N. Spergel , Matteo Viel

We discuss the origin and physical nature of the Lya forest absorption systems as found in hydrodynamical simulations of the Intergalactic Medium in a standard Cold Dark Matter cosmology (Omega=1, H0=50 km/s/Mpc, sigma_8=0.7). The…

Astrophysics · Physics 2009-10-26 Yu Zhang , Avery Meiksin , Peter Anninos , Michael L. Norman

Our understanding of the Lyman-$\alpha$ forest has received a great boost with the advent of the Keck Telescope and large 3D hydrodynamical simulations. We present new simulations using the SPH technique with a P^3MG (Particle-Particle…

Astrophysics · Physics 2007-05-23 J. W. Wadsley , J. Richard Bond

We estimate the value of the matter density parameter \Omega_0 by combining constraints from the galaxy cluster mass function with Croft et al.'s recent measurement of the mass power spectrum, P(k), from \lya forest data. The key assumption…

Astrophysics · Physics 2009-10-31 David H. Weinberg , Rupert A. C. Croft , Lars Hernquist , Neal Katz , Max Pettinini

We explore several physical effects on the power spectrum of the Lyman-alpha forest transmitted flux. The effects we investigate here are usually not part of hydrodynamic simulations and so need to be estimated separately. The most…

Astrophysics · Physics 2009-11-10 P. McDonald , U. Seljak , R. Cen , P. Bode , J. P. Ostriker

While the Lyman-$\alpha$ (Ly$\alpha$) forest traces the large-scale matter distribution over a wide range of redshift, its three-dimensional (3D) clustering at $z < 2$ has not yet been measured. We investigate the prospects for measuring…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Ting Tan , Huanyuan Shan , Eric Armengaud

We use a large set of cosmological smoothed particle hydrodynamics (SPH) simulations to examine the effect of mass resolution and box size on synthetic Lya forest spectra at 2 \leq z \leq 5. The mass resolution requirements for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 James S. Bolton , George D. Becker

We study the three-dimensional distribution of non virialised matter at z~2 using high resolution spectra of QSO pairs and simulated spectra drawn from cosmological hydrodynamical simulations. We have collected the largest sample of QSO…

Astrophysics · Physics 2009-11-11 V. D'Odorico , M. Viel , F. Saitta , S. Cristiani , S. Bianchi , B. Boyle , S. Lopez , J. Maza , P. Outram

We report the first detection at a median redshift $z = 2.49$ of large-scale matter flows around cosmic voids. Voids are identified within a tomographic map of large-scale Lyman-$\alpha$ (Ly$\alpha$) transmissions, built from the eBOSS…

We compare the low redshift (z ~ 0.1) Lyman-alpha forest from hydrodynamical simulations with data from the Cosmic Origin Spectrograph (COS). We find tension between the observed number of lines with b-parameters in the range 25-45 km/s and…

Astrophysics of Galaxies · Physics 2017-04-19 M. Viel , M. G. Haehnelt , J. S. Bolton , T. -S. Kim , E. Puchwein , F. Nasir , B. P. Wakker

Spectroscopy with HST/STIS Echelle and VLT/UVES of the bright QSO HE 0515-4414 (z_em =1.73, B = 15.0) offers for the first time the opportunity to study the Lyman alpha forest in the redshift range 0.9 < z < 1.7 at a resolution ~ 10 km/s.…

Astrophysics · Physics 2009-11-07 Eckart Janknecht , Robert Baade , Dieter Reimers

The average flux decrement shortward the Ly$_{\alpha}$ emission, due to the well-known ``forest'' of absorptions, has been measured in the spectra of 8 quasars. Quasi-simultaneous optical and IUE observations of the two low redshift quasars…

Astrophysics · Physics 2007-05-23 S. Cristiani , E. Giallongo , L. M. Buson , C. Gouiffes , F. La Franca

We present a study of the spatial coherence of the intergalactic medium toward two pairs of high-redshift quasars with moderate angular separations observed with Keck/ESI, Q1422+2309A/Q1424+2255 (z_em = 3.63, theta = 39") and Q1439-0034A/B…

Astrophysics · Physics 2009-11-10 George D. Becker , Wallace L. W. Sargent , Michael Rauch

(Abridged) Numerical simulations indicate that the intergalactic medium (IGM) responsible for the low column density Lyman-alpha forest follows a well defined temperature-density relation. We demonstrate that such an equation of state…

Astrophysics · Physics 2009-10-31 Joop Schaye , Tom Theuns , Anthony Leonard , George Efstathiou

We present a determination of the bispectrum of the flux in the Lyman-alpha forest of QSO absorption spectra obtained from LUQAS which consists of spectra observed with the high resolution Echelle spectrograph UVES. Typical errors on the…

Astrophysics · Physics 2009-11-10 M. Viel , S. Matarrese , A. Heavens , M. G. Haehnelt , T. -S. Kim , V. Springel , L. Hernquist

We propose a method for estimating the large-scale rms bulk velocity of the cosmic mass field from the transmitted fluxes of Ly$\alpha$ forests. It is based on two linear relationships on large scales: 1) the relation between the…

Astrophysics · Physics 2016-08-30 Hu Zhan , Li-Zhi Fang

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

[Abridged] We present FLO (From Lines to Over-densities), a new technique to reconstruct the hydrogen density field for the Lya forest lines observed in high resolution QSO spectra. The method is based on the hypothesis that the Lya lines…

Astrophysics · Physics 2009-11-13 F. Saitta , V. D'Odorico , M. Bruscoli , S. Cristiani , P. Monaco , M. Viel

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