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Gnedin, Yu. N.; Borisov, N. V.; Natsvlishvili, T. M.; Piotrovich, M. Yu.

doi:10.1023/a:1012815711233

Cited by 132 publications

(216 citation statements)

References 7 publications

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“…In each case we used pure particle mesh (PM) dark matter simulations, mimicking the temperature of the gas using a polytropic equation of state and assuming that gas and dark matter have the same spatial distribution. This has been shown (Petitjean et al 1995;Croft et al 1998;Gnedin & Hui 1998;Meiksin & White 2001) to produce results comparable to the full hydrodynamical simulations at the level of 10 per cent. The agreement is expected to be even better on the large scales of interest to this work.…”

Section: N U M E R I C a L S I M U L At I O N Smentioning

confidence: 53%

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The effects of ultraviolet background correlations on Lyα forest flux statistics

Meiksin¹,

White²

2004

Monthly Notices of the Royal Astronomical Society

116

223

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We examine the possible effects of ultraviolet (UV) background fluctuations on the pixel flux power spectrum and autocorrelation function of the Lyα forest due to a finite number of sources in an attenuating medium. We consider scenarios in which quasi‐stellar object (QSO) sources dominate the contribution to the UV background. To estimate their contribution, we use the QSO luminosity functions from the Two‐Degree Field and the Sloan Digital Sky Survey. We estimate self‐consistent values for the attenuation length at the Lyman edge through the intergalactic medium using particle mesh simulations of the Lyα forest, normalized by the measured mean Lyα flux. It is necessary to add the contribution from Lyman‐limit systems based on their measured statistical properties because the simulations are unable to reproduce the measured abundances of these systems, suggesting that their formation may involve more complex hydrodynamical processes than simple collapse into dark matter haloes. We examine the convergence properties of the flux power spectrum and autocorrelation function under differing assumptions regarding pressure smoothing. On the basis of our tests, we recommend that simulations used to estimate the flux power spectrum at high redshifts (z > 3) be performed in a box of comoving size at least 25 h−1 Mpc on a side and a comoving force mesh as fine as 30–60 h−1 kpc. The requirements become more severe at lower redshifts. Even with these specifications, we find that the flux autocorrelation function does not converge to better than 10 per cent on scales exceeding 3 per cent of the box size without added pressure smoothing. Much better convergence properties are obtained for the relative effects of the UV background fluctuations on the flux power spectrum. The background fluctuations increase the large‐scale power and suppress the power at intermediate scales. At z≤ 4, the effect is only at the few per cent level. By z= 5.5, however, the large‐scale power is boosted by more than 10 per cent, growing rapidly at higher redshifts, and suggesting that the flux power spectrum may serve as a useful tool for distinguishing QSO‐dominated UV background scenarios from those in which more abundant sources like galaxies dominate.

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Section: N U M E R I C a L S I M U L At I O N Smentioning

confidence: 53%

“…Parallel to the development of the full hydrodynamical simulations of the intergalactic medium (IGM) are pseudo-hydrodynamical schemes using pure gravity (Petitjean, Mücket & Kates 1995;Croft et al 1998;Gnedin & Hui 1998;Meiksin & White 2001). These simpler treatments are based on two key results from the full hydrodynamical computations.…”

Section: Introductionmentioning

confidence: 99%

The effects of ultraviolet background correlations on Lyα forest flux statistics

Meiksin¹,

White²

2004

Monthly Notices of the Royal Astronomical Society

116

223

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“…Modelling the flux power spectrum of the Lyman α forest accurately for given cosmological parameters is not as straightforward as modelling the CMB power spectra, and accurate numerical simulations are required. M05 modelled the flux power spectrum using a large number of hydro-particle mesh (HPM) simulations (Gnedin & Hui 1998;Viel, Haehnelt & Springel 2006), calibrated with a few full hydrodynamical simulations. VHS improved instead the effective bias method developed by C02 [see Gnedin & Hamilton (2002) and Zaldarriaga, Scoccimarro & Hui (2003) for a critical assessment of the errors involved], by using a grid of full hydrodynamical simulations run with the Tree-smoothed particle hydrodynamics (Tree-SPH) code (Springel, Yoshida & White 2001;Springel 2005) to infer the linear matter power spectrum.…”

Section: Lyman α Forest Data Setsmentioning

confidence: 99%

“…Measurements of the matter power spectrum from Lyman α forest data extend to smaller scales and probe a redshift range complementary to estimates of the matter power spectrum from the cosmic microwave background (CMB), galaxy surveys or weak gravitational lensing observations (e.g. Croft et al 1998Croft et al , 2002Gnedin & Hui 1998;McDonald et al 2000;Hui et al 2001;McDonald 2003;Viel et al 2003;Meiksin & White 2004;Viel, Haehnelt & Springel 2004b, hereafter VHS).…”

Section: Introductionmentioning

confidence: 99%

The Lyman α forest and WMAP year three

Viel

Haehnelt

Lewis

2006

Monthly Notices of the Royal Astronomical Society: Letters

108

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A combined analysis of cosmic microwave background (CMB) and Lyman α forest data can constrain the matter power spectrum from small scales of about 1 h−1 Mpc all the way to the horizon scale. The long lever arm and complementarity provided by such an analysis have previously led to a significant tightening of the constraints on the shape and the amplitude of the power spectrum of primordial density fluctuations. We present here a combined analysis of the WMAP three‐year results with Lyman α forest data. The amplitude of the matter power spectrum σ8 and the spectral index ns inferred from the joint analysis of high‐ and low‐resolution Lyman α forest data as analysed by Viel & Haehnelt are consistent with the new WMAP results to within 1σ. The joint analysis with the mainly low‐resolution data as analysed by McDonald et al. suggests a value of σ8 that is ∼2σ higher than that inferred from the WMAP three‐year data alone. The joint analysis of the three‐year WMAP and the Lyman α forest data also does not favour a running of the spectral index. The best‐fitting values for a combined analysis of the three‐year WMAP data, other CMB data, 2‐degree Field (2dF) data and the Lyman α forest data are (σ8, ns) = (0.78 ± 0.03, 0.96 ± 0.01).

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“…Note that the shape of the column‐density distribution is sensitive to the amount of large‐scale power (e.g. Gnedin 1998). This could be used to distinguish the effects of feedback from those of large‐scale power on the column‐density distribution.…”

Section: Feedback From Small Systemsmentioning

confidence: 99%

Observational signatures of feedback in QSO absorption spectra

Theuns

Schaye

2001

Monthly Notices of the Royal Astronomical Society

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Models for the formation of galaxies and clusters of galaxies require strong feedback in order to explain the observed properties of these systems. We investigate whether such feedback has observational consequences for the intergalactic medium, as probed in absorption towards background quasars. A typical quasar sight-line intersects one proto-cluster per unit redshift, and significant feedback from forming galaxies or AGN, heating the proto-cluster gas, will result in a large clearing of reduced absorption in the Lyman alpha-forest. Such a gap could be detected at redshift > 3 when the mean opacity is high. Feedback from Lyman-break galaxies in proto-clusters can be probed by the absorption lines produced in their winds. Strong feedback from galaxies has a major impact on the number and properties of absorption lines with neutral hydrogen column densities of 10^16/ cm^2. This feedback can be probed with multiple sight-lines and by studying the unsaturated higher-order lines of the Lyman series. Galactic winds from dwarf galaxies should break-up into clouds, in order not to over produce the number of absorption lines. These clouds can then coast to large distances.Comment: MNRAS published version (minor changes

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Cited by 132 publications

References 7 publications

The effects of ultraviolet background correlations on Lyα forest flux statistics

The effects of ultraviolet background correlations on Lyα forest flux statistics

The Lyman α forest and WMAP year three

Observational signatures of feedback in QSO absorption spectra

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