This web page gives access to the mock Sloan survey catalog described in the paper ``Topology from the Simulated Sloan Digital Sky Survey,'' by Colley, Gott, Weinberg, Park, and Berlind (1999, ApJ, submitted, astro-ph/9902332). The catalog is drawn from a large N-body simulation of a Lambda-CDM model and is extensively described in the paper. If you make use of the mock catalog in your own work, please reference the Colley et al. paper and this web site (Weinberg 1999) as the source.
The catalog is in gzip'ed ascii format, with one row for each of the 872,377 galaxies in the catalog. The columns in each row are
eta = survey latitude (degrees)
lambda = survey longitude (degrees)
z = redshift (dimensionless)
rc = comoving distance (h-1 Mpc)
dmax = maximum distance at which galaxy would pass selection criteria
(h-1 Mpc)
mP = Petrosian magnitude in r' band
As discussed in the paper, the selection criteria are an r' Petrosian magnitude limit of 17.9 and a half-light r' surface brightness threshold of 22 mag/arcsec2. To create a sample that is volume-limited out to a comoving distance D, eliminate all galaxies with rc > D or dmax < D.
The redshift includes both the cosmological redshift and the peculiar
velocity contribution. To get the peculiar velocity, use the formula
(1+z) = (1+zcosm)(1+vpec/c),
where zcosm is the cosmological redshift at the galaxy's
comoving distance in an Omega=0.4, Lambda=0.6 cosmology.
The approximation
r = 3000z - 940z2 + 130z3
has a maximum error of 0.46h-1 Mpc out to z=0.4.
To see the first few lines of the catalog in ascii form, click here.
Before you transfer the whole 15.5 Mbyte gzip'ed file, you might want to transfer a gzip'ed version of these first few lines and check that you get them correctly, by holding down the shift key and clicking here.
If you're ready to transfer the whole thing, hold the shift key and click here.
To access the mock catalogs from the paper by Cole, Hatton, Weinberg, and Frenk (1998, MNRAS, 300, 945), click here. A comparison of the relative merits of the Colley et al. and Cole et al. mock catalogs appears in Section 7 of the Colley et al. paper.