SIMBAD references

By means of high-resolution N-body simulations, we revisited the dissipationless collapse scenario for galaxy formation. We considered both single-component collapses and collapses of a cold stellar distribution in a live dark matter halo. Single-component collapses lead to stellar systems whose projected profiles are fitted very well by the Sersic R^1/m^ law with 3.6 ≲ m ≲ 8. The stellar end-products of collapses in a dark matter halo are still well described by the R^1/m^ law, but with 1.9 ≲ m ≲ 12, where the lowest m values are obtained when the halo is dominant. In all the explored cases, the profiles at small radii deviate from their global best-fitting R^1/m^ model, being significantly flatter. The break-radius values are comparable with those measured in `core' elliptical galaxies, and are directly related to the coldness of the initial conditions. The dissipationless collapse of initially cold stellar distributions in pre-existing dark matter haloes may thus have a role in determining the observed weak homology of elliptical galaxies.