Voronoi Tessellation and Non-parametric Halo Concentration

Abstract

We present and test TesseRACt, a non-parametric technique for recovering the concentration of simulated dark matter halos using Voronoi tessellation. TesseRACt is tested on idealized N-body halos that are axisymmetric, triaxial, and contain substructure and compared to traditional least-squares fitting as well as two non-parametric techniques that assume spherical symmetry. TesseRACt recovers halo concentrations within 0.3% of the true value regardless of whether the halo is spherical, axisymmetric, or triaxial. Traditional fitting and non-parametric techniques that assume spherical symmetry can return concentrations that are systematically off by as much as 10% from the true value for non-spherical halos. TesseRACt also performs significantly better when there is substructure present outside $0.5R_{200}$. Given that cosmological halos are rarely spherical and often contain substructure, we discuss implications for studies of halo concentration in cosmological N-body simulations including how choice of technique for measuring concentration might bias scaling relations.

8 figures, submitted to ApJ

References in corpus (13)

• GIZMO: A New Class of Accurate, Mesh-Free Hydrodynamic Simulation Methods
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The redshift dependence of the structure of massive LCDM halos
• The spin and shape of dark matter haloes in the Millennium simulation of a LambdaCDM universe
• ZOBOV: a parameter-free void-finding algorithm
• A universal model for halo concentrations
• Some like it triaxial: the universality of dark matter halo shapes and their evolution along the cosmic time
• The Voronoi Tessellation cluster finder in 2+1 dimensions
• Ellipsoidal halo finders and implications for models of triaxial halo formation
• The Effects of Varying Cosmological Parameters on Halo Substructure
• Phase-space structures I: A comparison of 6D density estimators
• Shape Profiles and Orientation Bias for Weak and Strong Lensing Cluster Halos

Cited by in corpus (5)

• DIVE in the cosmic web: voids with Delaunay Triangulation from discrete matter tracer distributions
• The mass function dependence on the dynamical state of dark matter haloes
• The Voronoi tessellation method in astronomy
• An efficient and robust method to estimate halo concentration
• Galaxy clustering in the VVV Near-IR Galaxy Catalogue