Accurate mass and velocity functions of dark matter haloes
Abstract
Nbody cosmological simulations are an essential tool to understand the observed distribution of galaxies. We use the MultiDark simulation suite, run with the Planck cosmological parameters, to revisit the mass and velocity functions. At redshift z = 0, the simulations cover four orders of magnitude in halo mass from ∼10^{11}M_{⊙} with 8783 874 distinct haloes and 532 533 subhaloes. The total volume used is ∼515 Gpc^{3}, more than eight times larger than in previous studies. We measure and model the halo mass function, its covariance matrix w.r.t halo mass and the largescale halo bias. With the formalism of the excursionset mass function, we explicit the tight interconnection between the covariance matrix, bias and halo mass function. We obtain a very accurate (<2 per cent level) model of the distinct halo mass function. We also model the subhalo mass function and its relation to the distinct halo mass function. The set of models obtained provides a complete and precise framework for the description of haloes in the concordance Planck cosmology. Finally, we provide precise analytical fits of the V_{max} maximum velocity function up to redshift z < 2.3 to push for the development of halo occupation distribution using V_{max}. The data and the analysis code are made publicly available in the Skies and Universes data base.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 August 2017
 DOI:
 10.1093/mnras/stx1183
 arXiv:
 arXiv:1702.01628
 Bibcode:
 2017MNRAS.469.4157C
 Keywords:

 dark matter;
 largescale structure of Universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 Corresponding data is available at the Skies and Universes data base: http://projects.ift.uamcsic.es/skiesuniverses