A dynamics-based density profile for dark haloes -- II. Fitting function

Abstract

The density profiles of dark matter haloes are commonly described by fitting functions such as the NFW or Einasto models, but these approximations break down in the transition region where halos become dominated by newly accreting matter. Here we present a simple, accurate new fitting function that is inspired by the asymptotic shapes of the separate orbiting and infalling halo components. The orbiting term is described as a truncated Einasto profile, ${\rho }_{\mathrm{orb}}\propto \exp \left[-2/\alpha (r/r_{\mathrm{s}}{)}^{\alpha }-1/\beta (r/r_{\mathrm{t}}{)}^{\beta }\right]$, with a five-parameter space of normalization, physically distinct scale and truncation radii, and $\alpha$ and $\beta$, which control how rapidly the profiles steepen. The infalling profile is modelled as a power law in overdensity that smoothly transitions to a constant at the halo centre. We show that these formulae fit the averaged, total profiles in simulations to about 5% accuracy across almost all of an expansive parameter space in halo mass, redshift, cosmology, and accretion rate. When fixing $\alpha =0.18$ and $\beta =3$, the formula becomes a three-parameter model that fits individual halos better than the Einasto profile on average. By analogy with King profiles, we show that the sharp truncation resembles a cut-off in binding energy.

arXiv comment20 pages, 10 figures. Additional figures at http://www.benediktdiemer.com/data

References in corpus (121)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• A Universal Density Profile from Hierarchical Clustering
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The Structure of Cold Dark Matter Halos
• Planck 2013 results. XVI. Cosmological parameters
• The cosmological simulation code GADGET-2
• Efficient Computation of CMB anisotropies in closed FRW models
• Halo Models of Large Scale Structure
• Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• The Structure of Dark Matter Haloes in Dwarf Galaxies
• Cold collapse and the core catastrophe
• Concentrations of Dark Halos from their Assembly Histories
• How Filaments are Woven into the Cosmic Web
• Simulations of X-ray Clusters
• The Inner Structure of LambdaCDM Halos III: Universality and Asymptotic Slopes
• The Inner Structure of LambdaCDM Halos I: A Numerical Convergence Study
• MultiDark simulations: the story of dark matter halo concentrations and density profiles
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Halos and galaxies in the standard cosmological model: results from the Bolshoi simulation
• The Diversity and Similarity of Simulated Cold Dark Matter Halos
• The Connection between Galaxies and their Dark Matter Halos
• The Core-Cusp Problem
• Analytical Models For Galactic Nuclei
• Transients from Initial Conditions in Cosmological Simulations
• Gravitationally Consistent Halo Catalogs and Merger Trees for Precision Cosmology
• Empirical models for Dark Matter Halos. I. Nonparametric Construction of Density Profiles and Comparison with Parametric Models
• Density profiles and substructure of dark matter halos: converging results at ultra-high numerical resolution
• The redshift dependence of the structure of massive LCDM halos
• COLOSSUS: A python toolkit for cosmology, large-scale structure, and dark matter halos
• Accurate universal models for the mass accretion histories and concentrations of dark matter halos
• The dependence of dark matter profiles on the stellar to halo mass ratio: a prediction for cusps vs cores
• Rotation-Dependent Catastrophic Disruption of Gravitational Aggregates
• Cusp-core transformations in dwarf galaxies: observational predictions
• Dependence of the outer density profiles of halos on their mass accretion rate
• Quantifying the heart of darkness with GHALO - a multi-billion particle simulation of our galactic halo
• A universal model for halo concentrations
• The Mass-Concentration-Redshift Relation of Cold and Warm Dark Matter Halos
• Properties of spherical galaxies and clusters with an NFW density profile
• Dark matter cores all the way down
• The splashback radius as a physical halo boundary and the growth of halo mass
• On the Accuracy of Weak Lensing Cluster Mass Reconstructions
• Galaxy Masses
• Imfit: A Fast, Flexible New Program for Astronomical Image Fitting
• Universal structure of dark matter haloes over a mass range of 20 orders of magnitude
• Structure of Dark Matter Halos From Hierarchical Clustering
• Splashback in accreting dark matter halos
• Tidal tails in CDM cosmologies
• The Mass Profile and Accretion History of Cold Dark Matter Halos
• A universal density slope - velocity anisotropy relation for relaxed structures
• The pseudo-evolution of halo mass
• Quantifying baryon effects on the matter power spectrum and the weak lensing shear correlation
• Detection of the Splashback Radius and Halo Assembly bias of Massive Galaxy Clusters
• The impact of galaxy formation on the total mass, mass profile and abundance of haloes
• Empirical Models for Dark Matter Halos. II. Inner profile slopes, dynamical profiles, and rho/sigma^3
• Analytic models of plausible gravitational lens potentials
• A dark matter profile to model diverse feedback-induced core sizes of $\Lambda$CDM haloes
• Detailed cluster lensing profiles at large radii and the impact on cluster weak lensing studies
• Density profiles of LCDM clusters
• How far do they go? The outer structure of dark matter halos
• Cluster-galaxy weak lensing
• Analytical properties of Einasto dark matter haloes
• Dark matter in elliptical galaxies: I. Is the total mass density profile of the NFW form or even steeper?
• The universal distribution of halo interlopers in projected phase space. Bias in galaxy cluster concentration and velocity anisotropy?
• The Halo Boundary of Galaxy Clusters in the SDSS
• A model for the postcollapse equilibrium of cosmological structure: truncated isothermal spheres from top-hat density perturbations
• The splashback radius of halos from particle dynamics. I. The SPARTA algorithm
• Numerical convergence of simulations of galaxy formation: the abundance and internal structure of cold dark matter haloes
• The core-cusp problem: a matter of perspective
• Lensing Constraints on the Mass Profile Shape and the Splashback Radius of Galaxy Clusters
• Measurement of the Splashback Feature around SZ-selected Galaxy Clusters with DES, SPT and ACT
• The Density and Pseudo-Phase-Space Density Profiles of CDM halos
• Conserved actions, maximum entropy and dark matter halos
• Statistical mechanics of collisionless orbits. I. Origin of central cusps in dark-matter halos
• Constraints on dark matter self-interaction from the internal density profiles of X-COP galaxy clusters
• The Dekel-Zhao profile: A mass-dependent dark-matter density profile with flexible inner slope and analytic potential, velocity dispersion, and lensing properties
• Spherical galaxy models with power law logarithmic slope
• Dark-Matter Halo Profiles of a General Cusp/Core with Analytic Velocity and Potential
• The splashback boundary of haloes in hydrodynamic simulations
• How Biased Are Halo Properties in Cosmological Simulations?
• A natural boundary of dark matter haloes revealed around the minimum bias and maximum infall locations
• Infall caustics in dark matter halos?
• Probing galaxy evolution in massive clusters using ACT and DES: splashback as a cosmic clock
• How Accurately Can We Detect the Splashback Radius of Dark Matter Halos and its Correlation With Accretion Rate?
• Is the Concentration of Dark Matter Halos at Virialization Universal ?
• Einasto Profiles and the Dark Matter Power Spectrum
• Dark Matter Halo Profiles in Scale-Free Cosmologies
• The splashback radius of optically selected clusters with Subaru HSC Second Public Data Release
• Fitting functions for dark matter density profiles
• The phase-space structure of tidally stripped halos
• Connecting the structure of dark matter haloes to the primordial power spectrum
• A Redefinition of the Halo Boundary Leads to a Simple yet Accurate Halo Model of Large Scale Structure
• The splashback radius of halos from particle dynamics: III. Halo catalogs, merger trees, and host-subhalo relations
• The Phase Space Structure of Dark Matter Halos
• Statistical mechanics of collisionless orbits. II. Structure of halos
• The Effects of Varying Cosmological Parameters on Halo Substructure
• Clusters Have Edges: The Projected Phase SpaceStructure of SDSS redMaPPer Clusters
• Splashback radius of nonspherical dark matter halos from cosmic density and velocity fields
• Intrinsic Alignments and Splashback Radius of Dark Matter Halos from Cosmic Density and Velocity Fields
• Statistical mechanics of collisionless orbits. III. Comparison with N-body simulations
• The orbital phase space of contracted dark matter halos
• LoCuSS: The splashback radius of massive galaxy clusters and its dependence on cluster merger history
• Illuminating Dark Matter Halo Density Profiles Without Subhaloes
• Phase-space structure of cold dark matter halos inside splashback: multi-stream flows and self-similar solution
• Insights into the origin of halo mass profiles from machine learning
• Cosmic structures from a mathematical perspective 1. Dark matter halo mass density profiles
• Kinematics of cluster galaxies and their relation to galaxy evolution
• The impact of galaxy selection on the splashback boundaries of galaxy clusters
• The Super-NFW model: an analytic dynamical model for cold dark matter haloes and elliptical galaxies
• The dynamical structure of broken power-law and double power-law models for dark matter haloes
• Detailed theoretical predictions of the outskirts of dark matter halos
• Surface mass density of the Einasto family of dark matter haloes: Are they Sersic-like?
• Stellar systems following the $R^{1/m}$ luminosity law. III. Photometric, intrinsic, and dynamical properties for all Sérsic indices
• Constraining cluster masses from the stacked phase space distribution at large radii
• Statistical mechanics of self-gravitating systems: mixing as a criterion for indistinguishability
• A deeper look into the structure of ΛCDM haloes: correlations between halo parameters from Einasto fits
• High-accuracy analytical solutions for the projected mass (counts) and surface density (brightness) of Einasto profiles
• Beyond Mass: Detecting Secondary Halo Properties with Galaxy-Galaxy Lensing
• Measuring the mass and concentration of dark matter halos from the velocity dispersion profile of their stars
• Observing Correlations Between Dark Matter Accretion and Galaxy Growth: II. Testing the Impact of Galaxy Mass, Star Formation Indicator, and Neighbour Colours

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• Deep Chandra Observations of the z = 1.16 Relaxed, Cool-core Galaxy Cluster SPT-CL J2215-3537
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• The Three Hundred Project: deducing the stellar splashback structure of galaxy clusters from their orbiting profiles
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• Distinguishing Orbiting and Infalling Dark Matter Particles with Machine Learning
• Galaxy Cluster Mass Estimation Through The Splashback Radius
• Mass scaling relations for dark halos from an analytic universal outer density profile
• STRAWBERRY: Finding haloes in the gravitational potential
• Hubble Expansion Signature on Simulated Halo Density Profiles: A Path to Observing the Turnaround Radius
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