Calibrating the Planck Cluster Mass Scale with CLASH

Understand

We determine the mass scale of Planck galaxy clusters using gravitational lensing mass measurements from the Cluster Lensing And Supernova survey with Hubble (CLASH).

• We have compared the lensing masses to the Planck Sunyaev-Zeldovich (SZ) mass proxy for 21 clusters in common, employing a Bayesian analysis to simultaneously fit an idealized CLASH selection function and the distribution between the measured observables and true cluster mass.
• We used a tiered analysis strategy to explicitly demonstrate the importance of priors on weak lensing mass accuracy.
• In the case of an assumed constant bias, $b_{SZ}$, between true cluster mass, $M_{500}$, and the Planck mass proxy, $M_{PL}$, our analysis constrains $1- b_{SZ} = 0.73\pm 0.10$ when moderate priors on weak lensing accuracy are used, including a zero-mean Gaussian with standard deviation of 8% to account for possible bias in lensing mass estimations.