Title: LoCuSS : Quantifying X-ray Mass Proxies for Cluster Cosmology
with Subaru Weak Lensing Program
Author(s): N. Okabe,
          Y.-Y. Zhang,
          A. Finoguenov,
          M. Takada,
          K. Umetsu,
          T. Futamase,
          & G. P. Smith,
Abstract:

We perform a joint, systematic weak gravitational lensing (Subaru/ 
Surpime-Cam) and  X-ray (XMM-Newton) analysis for galaxy clusters,  
unbiasedly selected from ROSAT All Sky Survey, to investigate mass- 
observable scaling relations. It is of critical importance to obtain a  
well-calibrated scaling relation and understand the bias and scatters,  
especially for the cosmological tool of cluster observables.

Weak lensing distortion of background galaxy images by a cluster  
allows to directly estimate cluster mass irrespective of the physical  
states. Therefore, by combining the lensing mass estimates with X-ray  
observables, we can directly explore a scaling relation between  
cluster mass and X-ray observables, including the scaling relation for  
the integrated intracluster gas pressure $Y_X=M_gas T$ that is  
expected to display a tighter scaling relation by numerical  
simulations.  Thus our method does not assume the hydrostatic  
equilibrium to estimate cluster mass as done in the usual X-ray based  
methods. We in detail study how the normalization and scatters of the  
scaling relation depend on properties of implied cluster dynamical  
stages/states (relaxed, unrelaxed and so on).