Astrophys. J., 767, 116 (2013/April-3)
Joint analysis of cluster observations. II. Chandra/XMM-Newton X-ray and weak lensing scaling relations for a sample of 50 rich clusters of galaxies.
MAHDAVI A., HOEKSTRA H., BABUL A., BILDFELL C., JELTEMA T. and HENRY J.P.
Abstract (from CDS):
We present a study of multiwavelength X-ray and weak lensing scaling relations for a sample of 50 clusters of galaxies. Our analysis combines Chandra and XMM-Newton data using an energy-dependent cross-calibration. After considering a number of scaling relations, we find that gas mass is the most robust estimator of weak lensing mass, yielding 15%±6% intrinsic scatter at rWL500 (the pseudo-pressure YX yields a consistent scatter of 22% ±5%). The scatter does not change when measured within a fixed physical radius of 1 Mpc. Clusters with small brightest cluster galaxy (BCG) to X-ray peak offsets constitute a very regular population whose members have the same gas mass fractions and whose even smaller (<10%) deviations from regularity can be ascribed to line of sight geometrical effects alone. Cool-core clusters, while a somewhat different population, also show the same (<10%) scatter in the gas mass-lensing mass relation. There is a good correlation and a hint of bimodality in the plane defined by BCG offset and central entropy (or central cooling time). The pseudo-pressure YX does not discriminate between the more relaxed and less relaxed populations, making it perhaps the more even-handed mass proxy for surveys. Overall, hydrostatic masses underestimate weak lensing masses by 10% on the average at rWL500; but cool-core clusters are consistent with no bias, while non-cool-core clusters have a large and constant 15%-20% bias between rWL2500 and rWL500, in agreement with N-body simulations incorporating unthermalized gas. For non-cool-core clusters, the bias correlates well with BCG ellipticity. We also examine centroid shift variance and power ratios to quantify substructure; these quantities do not correlate with residuals in the scaling relations. Individual clusters have for the most part forgotten the source of their departures from self-similarity.
galaxies: clusters: general - galaxies: clusters: intracluster medium - gravitational lensing: weak - X-rays: galaxies: clusters
erratum vol. 794, art. 175 (2014)
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