REVIEW 6 cited by
The Inner Structure of LambdaCDM Halos I: A Numerical Convergence Study
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
The Inner Structure of LambdaCDM Halos I: A Numerical Convergence Study
abstract
We present a comprehensive set of convergence tests which explore the role of various numerical parameters on the equilibrium structure of a simulated dark matter halo. We report results obtained with two independent, state-of-the-art, multi-stepping, parallel N-body codes: PKDGRAV and GADGET. We find that convergent mass profiles can be obtained for suitable choices of the gravitational softening, timestep, force accuracy, initial redshift, and particle number. For softenings chosen so that particle discreteness effects are negligible, convergence in the circular velocity is obtained at radii where the following conditions are satisfied: (i) the timestep is much shorter than the local orbital timescale; (ii) accelerations do not exceed a characteristic acceleration imprinted by the gravitational softening; and (iii) enough particles are enclosed so that the collisional relaxation timescale is longer than the age of the universe. The most stringent requirement for convergence is typically that imposed on the particle number by the collisional relaxation criterion, which implies that in order to estimate accurate circular velocities at radii where the density contrast may reach $\sim 10^6$, the region must enclose of order 3000 particles (or more than a few times $10^6$ within the virial radius). Applying these criteria to a galaxy-sized $\Lambda$CDM halo, we find that the spherically-averaged density profile becomes progressively shallower from the virial radius inwards, reaching a logarithmic slope shallower than -1.2 at the innermost resolved point, $r \sim 0.005 r_{200}$, with little evidence for convergence to a power-law behaviour in the inner regions.
Forward citations
Cited by 6 Pith papers
-
Cooling, conduction, compact objects: Gravothermal evolution of dissipative self-interacting dark matter halos
Dissipation in SIDM halos inverts heat conduction, suppresses isothermal cores, and explains an observed strong lens perturber with smaller cross sections or shorter times than the elastic case.
-
Do Primordial Black Hole Clusters Survive the Galaxy? Collisional Disruption and Microlensing Implications
Cluster-cluster collisions strip 50–96% of 10^6–10^7 M⊙ PBH cluster mass by z=0, so microlensing sightlines to the Magellanic Clouds are ~49–92% smooth.
-
Directional dark matter signatures of the Large Magellanic Cloud
Auriga simulations show the LMC induces azimuthal anisotropies in directional DM recoils that enhance discovery prospects relative to the Standard Halo Model.
-
The limits of feedback from active galactic nuclei
AGN feedback creates a mass-independent entropy ceiling that allows outflows to escape halos only below M_200m = 10^13.7 M_sun, explaining depleted gas in groups versus near-cosmic fractions in clusters.
-
MARVELously Dark: the density profile evolution of dwarf halos in velocity-dependent SIDM
In a new SIDM simulation of isolated dwarf halos, nine low-mass halos are core-collapsed, and inner density slope—rather than central density—best tracks collapse onset and matches analytic collapse-time predictions.
-
Cosmological simulations of the same spiral galaxy: satellite properties, the role of baryonic physics and star formation history in shaping dark matter cores/cusps
Satellites that form most of their stars early keep dark matter cusps, while late or continuous star formers develop oscillating cores, so the dwarf diversity problem may be explained by feedback history and tides wit...
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.