This directory contains mock LyA spectrum data generated for the purposes of testing IGM BAO. In all 8 particle mesh simulations were run, each using 30003 particles and a 30003 mesh in a periodic cube 1500Mpc/h on a side. The cosmology was a standard LCDM model with OmegaM=0.25, Lambda=0.75, h=0.75, n=0.97 and sigma8=0.8. The first 6 runs are simply different realizations of the same model, the last 2 are different and are used for convergence tests.
The data were dumped at z=2.5 (a=0.2857) and density and velocity fields generated from the particle positions and velocities along a regular grid of 22,500 lines-of-sight using a spline kernel interpolation. The effective smoothing was 250kpc/h, which is a little larger than ideal but still resolves much of the structure of interest for BAO. Missing or mis-modeled small-scale structure likely adds only a smooth component to the spectra at large scales.
For each line-of-sight the fluctuating Gunn-Peterson approximation (FGPA) was used to generate skewers of optical depth. We assumed a temperature at mean density of 2x104K and an equation of state gamma=1.5 (though other choices are possible). The optical depth included thermal broadening (assumed Gaussian) and skewers were generated both with and without peculiar velocities for the gas (the latter are "tau_real_*" below).
A Python script which indicates how to read the tau grids and compute mock spectra from them is available below (skewer.py). The lines-of-sight each contain 3,000 pixels and are stored sequentially in the file. The lines-of-sight form a regular Cartesian grid of 1502 points, with the y-index increasing most rapidly. I have also made available the real space mass density field, in the same format, along the same lines-of-sight. These are normalized to (approximately) the mean density, containing rho/bar[rho].
There are also some older/smaller simulations at this URL, which may be useful for some purposes, and some higher resolution simulations run as part of the Roadrunner project at this URL,
Last modified Fri Feb 19 08:07:05 2010