Cosmology and Astrophysics from Relaxed Galaxy Clusters V: Consistency with Cold Dark Matter Structure Formation

Abstract

This is the fifth in a series of papers studying the astrophysics and cosmology of massive, dynamically relaxed galaxy clusters. Our sample comprises 40 clusters identified as being dynamically relaxed and hot in Papers I and II of this series. Here we use constraints on cluster mass profiles from X-ray data to test some of the basic predictions of cosmological structure formation in the Cold Dark Matter (CDM) paradigm. We present constraints on the concentration--mass relation for massive clusters, finding a power-law mass dependence with a slope of ${\kappa }_m=-0.16\pm 0.07$, in agreement with CDM predictions. For this relaxed sample, the relation is consistent with a constant as a function of redshift (power-law slope with $1+z$ of ${\kappa }_{\zeta }=-0.17\pm 0.26$), with an intrinsic scatter of ${\sigma }_{\ln c}=0.16\pm 0.03$. We investigate the shape of cluster mass profiles over the radial range probed by the data (typically $\sim 50$kpc--1Mpc), and test for departures from the simple Navarro, Frenk & White (NFW) form, for which the logarithmic slope of the density profile tends to $-1$ at small radii. Specifically, we consider as alternatives the generalized NFW (GNFW) and Einasto parametrizations. For the GNFW model, we find an average value of (minus) the logarithmic inner slope of $\beta =1.02\pm 0.08$, with an intrinsic scatter of ${\sigma }_{\beta }=0.22\pm 0.07$, while in the Einasto case we constrain the average shape parameter to be $\alpha =0.29\pm 0.04$ with an intrinsic scatter of ${\sigma }_{\alpha }=0.12\pm 0.04$. Our results are thus consistent with the simple NFW model on average, but we clearly detect the presence of intrinsic, cluster-to-cluster scatter about the average.

8 pages, to appear in MNRAS. Minor typos corrected in v2

References in corpus (9)

• Testing X-ray Measurements of Galaxy Clusters with Cosmological Simulations
• The redshift dependence of the structure of massive LCDM halos
• Weighing the Giants IV: Cosmology and Neutrino Mass
• Cosmology and Astrophysics from Relaxed Galaxy Clusters II: Cosmological Constraints
• CLASH: The Concentration-Mass Relation of Galaxy Clusters
• The dark matter halos of massive, relaxed galaxy clusters observed with Chandra
• Cosmology and Astrophysics from Relaxed Galaxy Clusters I: Sample Selection
• X-ray properties in massive galaxy clusters: XMM-Newton observations of the REFLEX-DXL sample
• Galaxy cluster mass profiles

Cited by in corpus (3)

• The galaxy cluster mass scale and its impact on cosmological constraints from the cluster population
• The concentration-mass relation of clusters of galaxies from the OmegaWINGS survey
• Measuring cavity powers of active galactic nuclei in clusters using a hybrid X-ray-radio method -- A new window on feedback opened by subarcsecond LOFAR-VLBI observations