We report a scaling of the mean matter density with the width of the saturated Lyα absorptions. This property is established using the `pseudo-hydro' technique (Croft et al.). It provides a constraint for the inversion of the Lyα forest, which encounters difficulty in the saturated region. With a Gaussian density profile and the scaling relation, a simple inversion of the simulated Lyα forests shows that the one-dimensional mass power spectrum is well recovered on scales above 2 h-1 Mpc, or roughly k<~ 0.03 km-1 s, at z= 3. The recovery underestimates the power on small scales, but improvement is possible with a more sophisticated algorithm.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2003
- quasars: absorption lines;
- cosmology: theory;
- large-scale structure of Universe;
- 7 pages, 9 figures, accepted for publication in MNRAS, replaced by the version after proof