Open AccessClustering of galaxy clusters in cold dark matter universes
Author(s) -
Colberg J. M.,
White S. D. M.,
Yoshida N.,
MacFarland T. J.,
Jenkins A.,
Frenk C. S.,
Pearce F. R.,
Evrard A. E.,
Couchman H. M. P.,
Efstathiou G.,
Peacock J. A.,
Thomas P. A.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03832.x
Subject(s) - physics , cold dark matter , astrophysics , cluster (spacecraft) , galaxy cluster , spectral density , galaxy , dark matter , cosmological constant , mass distribution , cosmology , structure formation , statistics , theoretical physics , mathematics , computer science , programming language
We use very large cosmological N ‐body simulations to obtain accurate predictions for the two‐point correlations and power spectra of mass‐limited samples of galaxy clusters. We consider two currently popular cold dark matter (CDM) cosmogonies, a critical density model ( τ CDM) and a flat low density model with a cosmological constant (ΛCDM). Our simulations each use 10 9 particles to follow the mass distribution within cubes of side 2 h −1 Gpc ( τ CDM) and 3 h −1 Gpc (ΛCDM) with a force resolution better than 10 −4 of the cube side. We investigate how the predicted cluster correlations increase for samples of increasing mass and decreasing abundance. Very similar behaviour is found in the two cases. The correlation length increases from for samples with mean separation to for samples with The lower value here corresponds to τ CDM and the upper to ΛCDM. The power spectra of these cluster samples are accurately parallel to those of the mass over more than a decade in scale. Both correlation lengths and power spectrum biases can be predicted to better than 10 per cent using the simple model of Sheth, Mo & Tormen. This prediction requires only the linear mass power spectrum and has no adjustable parameters. We compare our predictions with published results for the automated plate measurement (APM) cluster sample. The observed variation of correlation length with richness agrees well with the models, particularly for ΛCDM. The observed power spectrum (for a cluster sample of mean separation ) lies significantly above the predictions of both models.