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. (arXiv:1210.3689v1 [astro-ph.CO])

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. (arXiv:1210.3689v1 [astro-ph.CO]):
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
r500. The scatter does not change when measured within a fixed physical radius
of 1 Mpc. Clusters with small 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 r500; but cool-core clusters are consistent with no bias,
while non-cool-core clusters have a large and constant 15-20% bias between
r2500 and r500, 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 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.