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Related papers: Systematic Continuum Errors in the Lyman-Alpha For…

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The high redshift galaxy MS1512-cB58 (z=2.724, m_V=20.64) has been observed with the very efficient high resolution echelle spectrograph VLT/UVES. Although this is a very challenging observational program for a Southern hemisphere telescope…

Astrophysics · Physics 2009-11-07 S. Savaglio , N. Panagia , P. Padovani

We present a measurement of the DLA mean bias from the cross-correlation of DLA and the Ly$\alpha$ forest, updating earlier results of Font-Ribera et al. 2012 with the final BOSS Data Release and an improved method to address continuum…

The quasar in the Hubble Deep Field South (HDFS), J2233-606 (z=2.23) has been exhaustively observed by ground based telescopes and by the STIS spectrograph on board the Hubble Space Telescope at low, medium and high resolution in the…

We present new measurements of the free-streaming of warm dark matter (WDM) from Lyman-$\alpha$ flux-power spectra. We use data from the medium resolution, intermediate redshift XQ-100 sample observed with the X-shooter spectrograph ($z=3 -…

Recent observations have discovered long (up to ~110 Mpc/h), opaque Gunn-Peterson troughs in the z ~ 5.5 Lyman-alpha forest, which are challenging to explain with conventional models of the post-reionization intergalactic medium. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-11 Frederick B. Davies , George D. Becker , Steven R. Furlanetto

We study the evolution with redshift of the number density of Ly$\alpha$ clouds in a CDM model using numerical simulations including photo-ionization and cooling of the baryonic component. The photo-ionizing flux is consistently taken as…

Astrophysics · Physics 2019-08-17 Jan P. Mücket , Patrick Petitjean , Ronald E. Kates , Rüdiger Riediger

Cosmological studies of the Lyman-Alpha (Lya) forest typically constrain parameters using two-point statistics. However, higher-order statistics, such as the three-point function (or its Fourier counterpart, the bispectrum) offer additional…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Roger de Belsunce , James M. Sullivan , Patrick McDonald

We present a neural network emulator to constrain the thermal parameters of the intergalactic medium (IGM) at $\displaystyle{5.4}\le{z}\le{6.0}$ using the Lyman-$\displaystyle\alpha$ (Ly$\displaystyle\alpha$) forest flux auto-correlation…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-24 Zhenyu Jin , Molly Wolfson , Joseph F. Hennawi , Diego González-Hernández

We re-examine the X-ray luminosity-temperature relation using a nearly homogeneous data set of 24 clusters selected for statistically accurate temperature measurements and absence of strong cooling flows. The data exhibit a remarkably tight…

Astrophysics · Physics 2009-10-30 Monique Arnaud , August E. Evrard

At low densities the standard ionisation history of the intergalactic medium (IGM) predicts a decreasing temperature of the IGM with decreasing density once hydrogen (and helium) reionisation is complete. Heating the high-redshift,…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 A. Rorai , G. D. Becker , M. G. Haehnelt , R. F. Carswell , J. S. Bolton , S. Cristiani , V. D'Odorico , G. Cupani , P. Barai , F. Calura , T. -S. Kim , E. Pomante , E. Tescari , M. Viel

We use published measurements of the transmission power spectrum of the Lyman alpha forest to constrain several parameters that describe cosmology and thermal properties of the intergalactic medium (IGM). A 6 parameter grid is constructed…

Astrophysics · Physics 2009-10-31 Matias Zaldarriaga , Lam Hui , Max Tegmark

Context. The overdensity inside a cosmological sub-volume and the tidal fields from its surroundings affect the matter distribution of the region. The resulting difference between the local and global power spectra is characterized by the…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 Gábor Rácz , István Szapudi , István Csabai

The main uncertainty in current determinations of the power spectrum normalization, sigma_8, from abundances of X-ray luminous galaxy clusters arises from the calibration of the mass-temperature relation. We use our weak lensing mass…

Astrophysics · Physics 2009-11-11 Kristian Pedersen , Haakon Dahle

The effective recombination coefficient, alpha_eff, is refined for optically thin cases. Radiation pressure in Lyman-alpha and HeII Lyman-alpha is calculated in terms of the number density and the mean free path. Pressure equilibrium…

Astrophysics · Physics 2007-05-23 Michael Fisher

Optical quasar spectra can be used to trace variations of the fine-structure constant alpha. Controversial results that have been published in last years suggest that in addition to to wavelength calibration problems systematic errors might…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nils Prause , Dieter Reimers

We have performed a detailed statistical study of the evolution of structure in a photoionized intergalactic medium (IGM) using analytical simulations to extend the calculation into the mildly non-linear density regime found to prevail at z…

Astrophysics · Physics 2008-11-26 HongGuang Bi , Arthur F. Davidsen

The standard cosmological analysis with the Ly$\alpha$ forest relies on a continuum fitting procedure that suppresses information on large scales and distorts the three-dimensional correlation function on all scales. In this work, we…

Fluctuations in Lyman-$\alpha$ (Ly$\alpha$) forest transmission towards high-$z$ quasars are partially sourced from spatial fluctuations in the ultraviolet background (UVB), the level of which are set by the mean free path of ionizing…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-10 Molly Wolfson , Joseph F. Hennawi , Frederick B. Davies , Jose Oñorbe

The temperature of the low-density intergalactic medium (IGM) at high redshift is sensitive to the timing and nature of hydrogen and HeII reionization, and can be measured from Lyman-alpha forest absorption spectra. Since the memory of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Adam Lidz , Matthew Malloy

(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