Aim

Most N-body comparison projects have focused on reproducing the same field halo (i.e., bulk properties like mass, profiles, dispersions). Ideally all numerical methods will have the same subhalo population and also produce the same galaxies, gas distributions, stellar halos, tidal debris, etc. The purpose of the substructure study is to examine whether codes give the same results in a highly nonlinear environment.

Projects

Subhalos/Galaxies

This study examines

1. whether the same dark matter subhalo distribution (mass, velocities, radial, etc) is produced by all the N-body codes in the nIFTY comparison project in (ideally) three types of simulations. Dark Mater only (DM), non-radiative adiabatic simulations (NR), and full radiative physics runs that attempt to model star formation and the processes governing galaxy formation (RAD). We also compare the gas content in NR simulations (and RAD) of these subhaloes.
2. whether the same subhaloes exist in all codes (object-by-object comparison), examining various bulk quantities like mass, vmax,rvmax, etc. 
3. how the subhalo population changes with the inclusion of a variety of physics (only surface scan of how it changes)
4. Finally we study the galaxies that form in the cluster environment (only surface comparison of galaxy population)

The comparison has been done for z=0.

Revision of paper (25/01/2016)

With diff from submission here (and old version here)

Comments: Please feel free to leave major comments about the scope/direction of the paper/project here.

Galaxies

This future work should be a detailed study of the underlying subgrid physics by comparing galaxies across codes. Given that the dark matter subhalo population is reasonably well aligned and reproduced, a detailed comparison of the galaxy population at z=0 and z=1 is warranted. I would like to see how various techniques affect the resulting galaxy, i.e., does kinetic SN feedback in SPH codes suppress small galaxies correctly at z=0 but this suppression is too high at z=1 but thermal works better in the opposite direction? What does this tell us about how energy is injected into the intergalactic medium. What about galaxies on the outskirts of a cluster? Do codes get the field galaxies correct but then fail to model the baryonic process that dominated in an infalling galaxy?

DATA (see tables for more info)

CLUSTER_00019: all nIFTY codes with DM, NR, FP  z=0.

Halo Catalogs: VELOCIraptor (variety of output formats)