Dark matter halo occupation: environment and clustering

Abstract

We use a large dark matter simulation of a LambdaCDM model to investigate the clustering and environmental dependence of the number of substructures in a halo. Focusing on redshift z=1, we find that the halo occupation distribution is sensitive at the tens of percent level to the surrounding density and to a lesser extent to asymmetry of the surrounding density distribution. We compute the autocorrelation function of halos as a function of occupation, building on the finding of Wechsler et al. (2006) and Gao and White (2007) that halos (at fixed mass) with more substructure are more clustered. We compute the relative bias as a function of occupation number at fixed mass, finding a strong relationship. At fixed mass, halos in the top 5% of occupation can have an autocorrelation function ~ 1.5-2 times higher than the mean. We also compute the bias as a function of halo mass, for fixed halo occupation. We find that for group and cluster sized halos, when the number of subhalos is held fixed, there is a strong anticorrelation between bias and halo mass. Such a relationship represents an additional challenge to the halo model.

13 pages, 10 figures, MNRAS submitted

References in corpus (16)

• The spin and shape of dark matter haloes in the Millennium simulation of a LambdaCDM universe
• Assembly bias in the clustering of dark matter haloes
• A GMBCG Galaxy Cluster Catalog of 55,424 Rich Clusters from SDSS DR7
• The Excursion Set Theory of Halo Mass Functions, Halo Clustering, and Halo Growth
• The overdensity and masses of the friends-of-friends halos and universality of the halo mass function
• The Clustering of Massive Halos
• Disentangling galaxy environment and host halo mass
• The statistics of the subhalo abundance of dark matter haloes
• The BigBOSS Experiment
• The correlation structure of dark matter halo properties
• Properties of Dark Matter Haloes and their Correlations: the Lesson from Principal Component Analysis
• Backsplash galaxies in isolated clusters
• Extrinsic Sources of Scatter in the Richness-Mass Relation of Galaxy Clusters
• Supermassive Black Holes and Their Environments
• Detecting neutral hydrogen in emission at redshift z ~ 1
• Counts-in-Cylinders in the Sloan Digital Sky Survey with Comparisons to N-body Simulations

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