The nearly universal merger rate of dark matter haloes in ΛCDM cosmology

We construct merger trees from the largest data base of dark matter haloes to date provided by the Millennium Simulation to quantify the merger rates of haloes over a broad range of descendant halo mass (1012≲M 0≲ 1015MȮ), progenitor mass ratio (10−3≲ξ≤ 1), and redshift (0 ≤z≲ 6). We find the mean...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society 2008, Vol.386 (2), p.577-592
Main Authors: Fakhouri, Onsi, Ma, Chung-Pei
Format: Article
Language:English
Subjects:
cosmology: theory
dark matter
galaxies: evolution
galaxies: formation
large-scale structure of Universe
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We construct merger trees from the largest data base of dark matter haloes to date provided by the Millennium Simulation to quantify the merger rates of haloes over a broad range of descendant halo mass (1012≲M 0≲ 1015MȮ), progenitor mass ratio (10−3≲ξ≤ 1), and redshift (0 ≤z≲ 6). We find the mean merger rate per halo, B/n, to have very simple dependence on M 0, ξ, and z, and propose a universal fitting form for B/n that is accurate to 10-20 per cent. Overall, B/n depends very weakly on the halo mass (∝M 0.08 0) and scales as a power law in the progenitor mass ratio (∝ξ−2) for minor mergers (ξ≲ 0.1) with a mild upturn for major mergers. As a function of time, we find the merger rate per Gyr to evolve roughly as (1 +z)
ISSN:0035-8711
1365-2966
DOI:10.1111/j.1365-2966.2008.13075.x