The mass function of dark matter haloes
Abstract
We combine data from a number of Nbody simulations to predict the abundance of dark haloes in cold dark matter (CDM) universes over more than four orders of magnitude in mass. A comparison of different simulations suggests that the dominant uncertainty in our results is systematic and is smaller than 1030per cent at all masses, depending on the halo definition used. In particular, our `Hubble volume' simulations of τCDM and ΛCDM cosmologies allow the abundance of massive clusters to be predicted with uncertainties well below those expected in all currently planned observational surveys. We show that for a range of CDM cosmologies and for a suitable halo definition, the simulated mass function is almost independent of epoch, of cosmological parameters and of the initial power spectrum when expressed in appropriate variables. This universality is of exactly the kind predicted by the familiar PressSchechter model, although this model predicts a mass function shape that differs from our numerical results, overestimating the abundance of `typical' haloes and underestimating that of massive systems.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 February 2001
 DOI:
 10.1046/j.13658711.2001.04029.x
 arXiv:
 arXiv:astroph/0005260
 Bibcode:
 2001MNRAS.321..372J
 Keywords:

 GRAVITATION;
 METHODS: NUMERICAL;
 COSMOLOGY: THEORY;
 DARK MATTER;
 gravitation;
 methods: numerical;
 cosmology: theory;
 dark matter;
 Astrophysics
 EPrint:
 14 pages, 12 figures, Minor changes. Accepted for publication in MNRAS