Kimmo KETTULA
(University of Helsinki)
We calibrated a scaling relation between weak lensing masses and X-ray spectroscopic temperatures for a sample of 10 galaxy groups in the COSMOS field and 25 clusters from litterature. Our sample expands weak lensing calibrated M-T relations to a lower mass and temperature range than previous studies. We obtained a slope consistent with the self-similar prediction, conflicting with previous galaxy group studies using hydrostatic mass estimates. We interpret this discrepancy as a deviation between hydrostatic and lensing masses, which is indicated by simulations. Our study provides the first observational support for this scenario.