High-Resolution Simulations of Cluster Formation

Abstract

The formation history of rich clusters is investigated using a hybrid N-body simulation in which high spatial and mass resolution can be achieved self-consistently within a small region of a very large volume. The evolution of three massive clusters is studied via mass accretion, spherically-averaged density profiles, three-dimensional and projected shapes, and degree of substructure. Each cluster consists of order $4\times 10^5$ particles at the present epoch and in the case that rich cluster evolution is well-described by a 1-parameter family, the simulations have sufficient resolution to demonstrate this. At $z=0$ the clusters have similar masses, $M(r\le 1.5h^{-1}Mpc)\sim 2\times 10^{15}{h}^{-1}{M}_{\odot }$, and similar spherically-averaged density profiles, however markedly different formation histories are observed. No single, dominant pattern is apparent in the time variation of the mass accretion rate, the cluster shape, or the degree of substructure. Although not a statistically large sample, these objects suggest that the detailed formation history of rich clusters cannot be characterized by a simple 1-parameter family. These results suggest that the use of observations of rich clusters over a wide range of redshifts to constrain cosmological parameters may not be entirely straightforward.

28 pages, 8 figures, plain TeX

References in corpus (6)

• A Universal Density Profile from Hierarchical Clustering
• Resolving the Structure of Cold Dark Matter Halos
• A Comparison of Direct and Indirect Mass Estimates for Distant Clusters of Galaxies
• QSO Absorbing Galaxies at z<~1: Deep Imaging and Spectroscopy in the Field of 3C 336
• A Massive Cluster of Galaxies at z = 0.996
• A Weak Lensing Survey in the Fields of z~1 Luminous Radio Sources

Cited by in corpus (12)

• Cold collapse and the core catastrophe
• Density profiles and substructure of dark matter halos: converging results at ultra-high numerical resolution
• Disruption of Dark Matter Substructure: Fact or Fiction?
• Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
• Structure of Dark Matter Halos From Hierarchical Clustering
• Substructure in Dark Halos: Orbital Eccentricities and Dynamical Friction
• Dissecting the Evolution of Dark Matter Subhaloes in the Bolshoi Simulation
• The Mass, Baryonic Fraction, and X-ray Temperature of the Luminous, High Redshift Cluster of Galaxies, MS0451.6-0305
• An Examination of the Optical Substructure of Galaxy Clusters Hosting Radio Sources
• Gravitational Lensing by Galaxy Groups in the Hubble Deep Field
• A Comparison of Simple Mass Estimators for Galaxy Clusters
• Constraining Lambda using cluster quadrupoles