The data is the famous Aquarius simulation (Springel et al. 2008) at various resolution levels:

level

Aq-5

Aq-4

Aq-3

Aq-2

Aq-1

# particles in halo

        2.300.000

      18.500.000

    148.300.000

    531.600.000

          a lot!

# of SUBFIND subhaloes

                 299

               1960

             13854

             45024

          quite some!

The simulation data as well as all post-processed halo catalogues can be found under the account notts2011@popia.ft.uam.es for which the password can be obtained from the SOC.

The data for this project is from the Virgo Consortium and permission is granted for this project only; if you would like to carry out any other project with it contact Carlos Frenk.

Please note that the number of subhaloes listed above are a guidance only and not to be taken as a target to hit with your code; they are derived with SUBFIND using some criteria we will not reveal here ;-)