Resolving the Structure of Cold Dark Matter Halos

By Anatoly Klypin, Andrey V. Kravtsov, James S. Bullock, Joel R. Primack. 2000

353 citations recorded by the source corpus.

We present results of a convergence study in which we compare the density profiles of cold dark matter halos simulated with varying mass and force resolutions. We show that although increasing the mass and force resolution allows one to probe deeper into the inner halo regions, the halo profiles converge on scales larger than the "effective" spatial resolution of the simulation. This resolution is defined by both the force softening and the mass resolution. On radii larger than the "effective" spatial resolution, density profiles do not experience any systematical trends when the number of particles or the force resolution increases further. In the simulations presented in this paper, we are able to probe the density profile of a relaxed isolated galaxy-size halo on scales r = (0.005-1)rvir. We find that the density distribution at resolved scales can be well approximated by the profile suggested by Moore and coworkers: ρ ∝ x-1.5(1 + x1.5)-1, where x = r/rs and rs is the characteristic radius. The analytical profile proposed by Navarro and coworkers, ρ ∝ x-1(1 + x)-2, also provides a good fit, with the same relative errors of about 10% for radii larger than 1% of the virial radius. For this limit, both analytical profiles fit well because for high-concentration galaxy-size halos, the differences between these profiles become significant only on scales well below 0.01rvir. We also find that halos of similar mass may have density profiles with somewhat different parameters (characteristic radius, maximum rotation velocity, etc.) and shapes. We associate this scatter in properties with differences in halo merger histories and with the amount of substructure present in the analyzed halos.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/b0d93809fbae6d7f8812130201f365b3ce479768

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Citations in the corpus

The Core-Cusp Problem (2009, background): “[20] derived slopes α = −1.”
Statistics of Physical Properties of Dark Matter Clusters (2005, background): “There has been much recent discussion (e.g., Klypin et al. 2001; Power et al. 2003; Hayashi et al. 2004) regarding the conditions that must be satisfied in order to ensure numerical convergence at the innermost radius to which the circular velocity profiles are computed.”
NIHAO – IV: core creation and destruction in dark matter density profiles across cosmic time (2015, background): “…pointed out by Navarro, Frenk and White (1997, NFW) and then confirmed via higher resolution numerical simulations by a large variety of works (e.g., Klypin et al. 2001, Diemand et al. 2004; Power et al. 2003, Macciò etal 2007, 2008, Neto et al. 2007, Navarro et al. 2010, Prada et al.2012,…”
DARK MATTER HALOS IN THE STANDARD COSMOLOGICAL MODEL: RESULTS FROM THE BOLSHOI SIMULATION (2010, background): “…corresponding to the maximum circular velocity, then we can write the following relation between the maximum circular velocity and the virial mass (Klypin et al. 2001): Vcirc = [ G f(xmax) f(c) c xmax ρ̂1/3 ]1/2 Mvir 1/3,(3) ρ̂ = Mvir Rvir 3 = 4π 3 ∆virρcrΩM, (4) f(x) = ln(1 + x) − x 1 + x ,…”
A primer on hierarchical galaxy formation: the semi-analytical approach (2006, background): “…matter haloes has been studied extensively over the past decade and a half using computer simulations (Dubinski & Carlberg 1991; Navarro, Frenk & White 1996, 1997; Moore et al. 1998; Fukushige & Makino 1997, 2001; Klypin et al. 2001; Power et al. 2003; Hayashi et al. 2004; Navarro et al. 2004).”
Formation and Structure of Halos in a Warm Dark Matter Cosmology (2000, methodology): “The halo density proÐle can be studied with high conÐdence only for radii larger than D4 times the formal force resolution (Klypin et al. 2001) and containing within them more than 50È100 particles.”
The inner structure of ΛCDM haloes – I. A numerical convergence study (2002, background): “Clearly, 100 particles are not enough to trace reliably the mass profile of a simulated halo, in disagreement with the conclusions of Klypin et al. (2001), who argue that 100-200 particles suffice c© 2002 RAS, MNRAS 000, 1–19 to resolve the inner mass profile when other parameters are chosen…”
Universal gas density and temperature profile (2001, background): “Although the universal profile does not explain the dark matter profiles onan object to object basis (Jing & Suto 2000; Klypin et al. 2001), itis still successful in fitting the averaged form of the dark matter density profiles with reasonable accuracy.”
Multiscale phenomenology of the cosmic web (2010, methodology): “Additionally we generated 2563 and 1283 versions following the “averaging” prescription described in (Klypin et al. 2001).”
The dark matter haloes of massive, relaxed galaxy clusters observed with Chandra (2006, background): “However, a consistent view has now emerged in which real dispersion is expected between the inner slopes for individual halos (Klypin et al. 2001; Tasitsiomi et al. 2004) and where typical values for the inner slopes of clusters lie in the range α ∼ 1.1 ± 0.4 (Navarro et al. 2004; Diemand et al.…”
THE CENTRAL SLOPE OF DARK MATTER CORES IN DWARF GALAXIES: SIMULATIONS VERSUS THINGS (2010, neutral): “The ΛCDM simulations have invariably predicted a dark matter density distribution which diverges toward the centers of galaxies (Moore 1994; Navarro, Frenk & White 1996, 1997; Moore et al. 1999b; Ghigna et al. 2000; Electronic address: seheon oh@ast.uct.ac.za Electronic address: cbbrook@uclan.ac.uk ”
The redshift dependence of the structure of massive Λ cold dark matter haloes (2007, background): “…do not take arbitrary values, but are instead correlated in a way that reflects the mass-dependence of halo assembly times (e.g., Kravtsov, Klypin & Khokhlov 1997; Avila-Reese et al. 1999; Jing 2000; Ghigna et al. 2000; Bullock et al. 2001; Eke, Navarro & Steinmetz 2001; Klypin et al. 2001).”
The Dark Matter Distribution in the Central Regions of Galaxy Clusters: Implications for Cold Dark Matter (2003, background): “Subsequent higher resolution work (e.g. Ghigna et al. 2000; Klypin et al. 2001) focused on the issue of convergence and reported that their results for the DM density profile were reliable down to scales of ∼50 kpc at the cluster scale, both groups found β ∼1.5.”
Dwarf galaxies in voids: suppressing star formation with photoheating (2005, methodology): “Using the mass refinement technique described by Klypin et al. (2001), we simulate void regions with high mass resolution, embedded in a proper cosmological en- vironment.”
HIGH-RESOLUTION ROTATION CURVES AND GALAXY MASS MODELS FROM THINGS (2008, background): “This density profile has a characteristic steep mass– density slope in the inner parts which can be approximated with a power-law ρ ∼ rα with α −1; this is the so-called “cusp” (e.g., Navarro et al. 1996, 1997; Klypin et al. 2001; Hayashi et al. 2004; Diemand et al. 2005).”