Modelling galaxy clustering: halo occupation distribution versus subhalo matching

Understand

We model the luminosity-dependent projected and redshift-space two-point correlation functions (2PCFs) of the Sloan Digital Sky Survey (SDSS) DR7 Main galaxy sample, using the halo occupation distribution (HOD) model and the subhalo abundance matching (SHAM) model and its extension.

• All the models are built on the same high-resolution $N$-body simulations.
• We find that the HOD model generally provides the best performance in reproducing the clustering measurements in both projected and redshift spaces.
• The SHAM model with the same halo-galaxy relation for central and satellite galaxies (or distinct haloes and subhaloes), when including scatters, has a best-fitting $\chi^2/\rm{dof}$ around $2$--$3$.