A simulated tau CDM cosmology cluster catalogue: the NFW profile and the temperature-mass scaling relations

We have extracted over 400 clusters, covering more than two decades in mass , from three simulations of the tau CDM cosmology. This represents the larg est uniform catalogue of simulated clusters ever produced. The clusters exh ibit a wide variety of density profiles. Only a minority are well-fitted in their outer regions by the widely used density profile of Navarro, Frenk & White (NFW), which is applicable to relaxed haloes, Others have steeper ou ter density profiles, show sharp breaks in their density profiles, or have significant substructure. If we force a fit to the NFW profile, then the be st-fitting concentrations decline with increasing mass, but this is driven primarily by an increase in substructure as one moves to higher masses. The temperature-mass relations for properties measured within a sphere enclosi ng a fixed overdensity all follow the self-similar form, T proportional to M-2/3; however, the normalization is lower than the value inferred for obse rved clusters. The temperature-mass relations for properties measured withi n a fixed physical radius are significantly steeper then this. Both can be accurately predicted using the NFW model.