Properties of galaxy haloes in clusters and voids

We use the results of a high-resolution N -body simulation to investigate the role of the environment on the formation and evolution of galaxy-sized haloes. Starting from a set of constrained initial conditions, we have produced a final configuration hosting a double cluster in one octant and a large void extending over two octants of the simulation box. In this paper we concentrate on gravitationally bound galaxy-sized haloes extracted from these two regions and from a third region hosting a single, relaxed cluster without substructure. Exploiting the high mass resolution of our simulation (m body =2.1 7109 h -1 Msolar ), we construct halo samples probing more than two decades in mass, starting from a rather small mass threshold: 5 71010 h -1 Msolar =34.2r 0 , where r 0 is the core radius of the TIS solution). We do, however, find a dependence of this relationship on the environment, like for the P (lambda ) statistics. These facts hint at a possible role of tidal fields in determining the statistical properties of haloes