We test the assumption of hydrostatic equilibrium in an X-ray luminosity selected sample of 50 galaxy clusters at 0.15 < z < 0.3 from the Local Cluster Substructure Survey ( LoCuSS ) .
Our weak-lensing measurements of M _ { 500 } control systematic biases to sub-4 per cent , and our hydrostatic measurements of the same achieve excellent agreement between XMM-Newton and Chandra .
The mean ratio of X-ray to lensing mass for these 50 clusters is \mathrel { \beta _ { X } } = 0.95 \pm 0.05 , and for the 44 clusters also detected by Planck , the mean ratio of Planck mass estimate to LoCuSS lensing mass is \mathrel { \beta _ { P } } = 0.95 \pm 0.04 .
Based on a careful like-for-like analysis , we find that LoCuSS , the Canadian Cluster Comparison Project ( CCCP ) , and Weighing the Giants ( WtG ) agree on \mathrel { \beta _ { P } } \simeq 0.9 - 0.95 at 0.15 < z < 0.3 .
This small level of hydrostatic bias disagrees at \sim 5 \sigma with the level required to reconcile Planck cosmology results from the cosmic microwave background and galaxy cluster counts .