Cross-calibration of cluster mass-observables and dark energy.

摘要

This paper is a first step towards developing a formalism to optimally extract dark energy information from number counts using multiple cluster observation techniques. We use a Fisher matrix analysis to study the improvements in the joint dark energy and cluster mass-observables constraints resulting from combining cluster counts and clustering abundances measured with different techniques. We use our formalism to forecast the constraints in O DE and w from combining optical and sz cluster counting on a 4000 sq. degree patch of sky. We find that this joint "self-calibration" yields ∼ 41-64% better constraints on O DE and w compared to simply adding the Fisher matrices of the individually self-calibrated counts. The joint constraints are less sensitive to variations in the mass threshold or maximum redshift range. A by-product of our technique is that the correlation between different mass-observables is well constrained without the need of additional priors on its value. Finally, we compare results from combining optical and sz surveys to two sz-like surveys and find that combining surveys with different properties yields the best constraints.