LoCuSS: Comparison of Observed X-ray and Lensing Galaxy Cluster Scaling Relations with Simulations

The Local Cluster Substructure Survey (LoCuSS, Smith et al.) is a systematic multi-wavelength survey of >100 X-ray luminous galaxy clusters (0.14<z<0.3) selected from the ROSAT all sky survey. We used data on 37 LoCuSS clusters from the XMM-Newton archive to investigate the global scaling relations of galaxy clusters. The scaling relations based solely on the X-ray data obey empirical self-similarity and reveal no additional evolution beyond the LSS growth. Weak lensing mass measurements are also available in the literature for 19 of the clusters with XMM-Newton data. The average of the weak lensing mass to X-ray based mass ratio is 1.09+/-8, setting the limit of the non-thermal pressure support to 9+/-8%. The mean of the weak lensing mass to X-ray based mass ratio of these clusters is ~1 with 31-51% scatter. The scatter in the mass--observable relations (M-Y_X, M-M_{gas} and M-T) is smaller using X-ray based masses than using weak lensing masses by a factor of 2. Using the scaled radius defined by the Y_X profile, we obtain lower scatter in the weak lensing mass based mass--observable relations. The normalization of the M-Y_X relation (also M-M_{gas} and M-T relations) using X-ray (weak lensing) mass estimates is lower than the one from simulations by up to 20% at ~3 sigma (~2 sigma) significance. Despite the large scatter in the X-ray to lensing comparison, the agreement between these two completely independent observational methods is an important step towards controlling astrophysical and measurement systematics in cosmological scaling relations.