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
Creators
- 1. Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94131 (United States)
- 2. Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands)
- 3. Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada)
- 4. Santa Cruz Institute for Particle Physics, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)
- 5. Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
Description
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 r500WL (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 r500WL; but cool-core clusters are consistent with no bias, while non-cool-core clusters have a large and constant 15%-20% bias between r2500WL and r500WL, 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.
Availability note (English)
Available from http://dx.doi.org/10.1088/0004-637X/767/2/116Additional details
Identifiers
Publishing Information
- Journal Title
- Astrophysical Journal
- Journal Volume
- 767
- Journal Issue
- 2
- Journal Page Range
- [18 p.]
- ISSN
- 0004-637X
- CODEN
- ASJOAB
INIS
- Country of Publication
- United States
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 44082007
- Subject category
- S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
- Descriptors DEI
- CALIBRATION; GALAXY CLUSTERS; GRAVITATIONAL LENSES; MASS; PEAKS; SCALING; SIMULATION; X RADIATION; X-RAY GALAXIES
- Descriptors DEC
- COSMIC RAY SOURCES; COSMIC X-RAY SOURCES; ELECTROMAGNETIC RADIATION; GALAXIES; IONIZING RADIATIONS; LENSES; RADIATIONS