Hubble Volume Mock 2dF, 6dF, PSCz and SDSS Galaxy Redshift Catalogues
Hubble Volume Mock APM, 2dF,6dF, PSCz and SDSS
by Shaun Cole, Carlton Baugh, Enzo Branchini, Steve Hatton
and the VIRGO consortium
The mock catalogues which are available here are extracted from
the 1 billion particle N-body simulations performed by the
VIRGO consortium of volumes approaching the size of the entire
If you make use of Hubble Volume data downloaded from this site
please let us know by dropping a short email to Prof C.S.Frenk@durham.ac.uk .
Please acknowledge both the Durham astrophysics theory group
and the VIRGO consortium in any papers you produce that make use of these
The methods of generating the mock catalogues
is the same as for the original published mock catalogues
(Cole etal MNRAS 1998 300, 945) .
The only biasing scheme
that was utilised is bias model 2, which is a 2-parameter
model based on the final density field.
These catalogues have been stored as (gzipped) ASCII files
and hopefully their content needs little
Three different sets of Hubble Volume mock catalogues are
available in the following three directories:
LambdaCDM03 which date
from June 2002
LambdaCDM04 which date
from december 2003 and are the catalogues used in the analysis
of the Cole etal 2005 2dFGRS power spectrum analysis. They differ
from the LambdaCDM03 in just two minor ways. The k+e correction
used in the selection was tweaked and so were the bias parameters.
differ from the previous in that the observers were placed at
random rather that locations picked to fit Local Group constraints.
See the information described and linked below for details.
Mock APM, 2dF, PSCz and 6dF catalogues
This set all have "Local Group" observers and the
position and orientation of the observer is the
same in the corresponding APM, 2dF, 6dF and PSCz
- The large volume of the simulation box (L= 2000 Mpc/h for TauCDM)
means that long wavelengths are well represented and
many essentially independent APM, 2dF, 6dF, PSCz or SDSS volumes can be
drawn from a single simulation.
- We have used a more realistic k+e correction
for the model galaxies and tuned the
bias parameters and luminosity function to produce a
selection function and clustering
that is a reasonable match to that of the
genuine galaxy redshift survey data.
- We have not chosen the observer at random but instead
observers which satisfy a certain set
of constraints which effectively make the observer
live in a region with similar properties to the Local
- Rather than generating the 2dF SGP catalogue we have
generated a larger catalogue covering the full area
of the published APM catalogue down to a magnitude of
Bj=20.5 . Also the NGP region has been extended over a
larger delcination range than will be targetted in the
2dF redshift survey. Software to extract the precise
2dF regions from this is available.
Note that it is an idealised catalogue
and we have the software to cut out the holes around
bright stars etc in the genuine catalogue.
- We have generated one catalogue with the
selection characteristics of the full SDSS photometric
catalogue. The Hubble Volume simulation is the only
one large enough to make this feasible.
- We do not have a wide range of different cosmological models.
At present there is just a TauCDM model and a
LambdaCDM model. Nor do we have a range of different
Thus these catalogues are not as useful as the original
set for testing the robustness of analysis techniques.
- The mass resolution is slightly poorer than in the orginals.
The mean particle seperation is 2 Mpc/h as opposed to 1.8 Mpc/h .