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
- Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94131 (United States)
- Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands)
- Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada)
- Santa Cruz Institute for Particle Physics, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)
- Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
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 r{sub 500}{sup WL} (the pseudo-pressure Y{sub X} 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 Y{sub X} 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 r{sub 500}{sup WL}; but cool-core clusters are consistent with no bias, while non-cool-core clusters have a large and constant 15%-20% bias between r{sub 2500}{sup WL} and r{sub 500}{sup WL}, 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.
- OSTI ID:
- 22126928
- Journal Information:
- Astrophysical Journal, Vol. 767, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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