Mon. Not. R. Astron. Soc., 369, 734-750 (2006/June-3)
The matter power spectrum from the Lyα forest: an optical depth estimate.
ZAROUBI S., VIEL M., NUSSER A., HAEHNELT M. and KIM T.-S.
Abstract (from CDS):
We measure the matter power spectrum from 31 Lyα spectra spanning the redshift range of 1.6-3.6. The optical depth, τ, for Lyα absorption of the intergalactic medium is obtained from the flux using the inversion method of Nusser & Haehnelt. The optical depth is converted to density by using a simple power-law relation, τ ∝ (1 + δ)α. The non-linear 1D power spectrum of the gas density is then inferred with a method that makes simultaneous use of the one- and two-point statistics of the flux and compared against theoretical models with a likelihood analysis. A cold dark matter model with standard cosmological parameters fits the data well. The power-spectrum amplitude is measured to be (assuming a flat Universe), σ8= (0.92±0.09)x(Ωm/0.3)–0.3, with α varying in the range of 1.56-1.8 with redshift. Enforcing the same cosmological parameters in all four redshift bins, the likelihood analysis suggests some evolution in the temperature-density relation and the thermal smoothing length of the gas. The inferred evolution is consistent with that expected if reionization of Heii occurred at z ∼ 3.2. A joint analysis with the Wilkinson Microwave Anisotropy Probe results together with a prior on the Hubble constant as suggested by the Hubble Space Telescope key project data, yields values of Ωmand σ8that are consistent with the cosmological concordance model. We also perform a further inversion to obtain the linear 3D power spectrum of the matter density fluctuations.
2006 The Authors. Journal compilation © 2006 RAS
hydrodynamics - intergalactic medium - quasars: absorption lines - cosmology: theory - large-scale structure of Universe
In fig. 1 : HS 1946-7658 is probably a misprint for HS 1946+7658
View the reference in ADS
To bookmark this query, right click on this link: simbad:2006MNRAS.369..734Z and select 'bookmark this link' or equivalent in the popup menu