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,
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Last modified Fri Feb 19 08:07:05 2010