Statistics of Dark Matter Substructure: I. Model and Universal Fitting Functions

Abstract

We present a new, semi-analytical model describing the evolution of dark matter subhaloes. The model uses merger trees constructed using the method of Parkinson et al. (2008) to describe the masses and redshifts of subhaloes at accretion, which are subsequently evolved using a simple model for the orbit-averaged mass loss rates. The model is extremely fast, treats subhaloes of all orders, accounts for scatter in orbital properties and halo concentrations, and uses a simple recipe to convert subhalo mass to maximum circular velocity. The model accurately reproduces the average subhalo mass and velocity functions in numerical simulations. The inferred subhalo mass loss rates imply that an average dark matter subhalo loses in excess of 80 percent of its infall mass during its first radial orbit within the host halo. We demonstrate that the total mass fraction in subhaloes is tightly correlated with the `dynamical age' of the host halo, defined as the number of halo dynamical times that have elapsed since its formation. Using this relation, we present universal fitting functions for the evolved and unevolved subhalo mass and velocity functions that are valid for any host halo mass, at any redshift, and for any ΛCDM cosmology.

arXiv comment20 pages, 11 figures, 1 table; submitted to MNRAS; for associated code that computes (best-fit) subhalo mass/velocity functions, see http://www.astro.yale.edu/jiang/Tool.html

References in corpus (2)

• Generating Merger Trees for Dark Matter Haloes: A Comparison of Methods
• Mass distribution and accretion of sub-halos

Cited by in corpus (12)

• The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
• A unified model for the spatial and mass distribution of subhaloes
• Coming of Age in the Dark Sector: How Dark Matter Haloes grow their Gravitational Potential Wells
• Warm Dark Matter Constraints Using Milky-Way Satellite Observations and Subhalo Evolution Modeling
• The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data
• On the Segregation of Dark Matter Substructure
• Resolution-independent modeling of environmental effects in semi-analytic models of galaxy formation that include ram-pressure stripping of both hot and cold gas
• Subhalo statistics of galactic halos: beyond the resolution limit
• Comprehensive Assessment of the Too-Big-to-Fail Problem
• The Next Generation Virgo Cluster Survey. IX. Estimating the Efficiency of Galaxy Formation on the Lowest-Mass Scales
• Clustering Constraints on the Relative Sizes of Central and Satellite Galaxies
• The Influence of Subhaloes on Host Halo Properties