Calibrating the Planck Cluster Mass Scale with CLASH
  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. Our analysis explicitly accounts for possible selection bias
effects in this calibration sourced by the CLASH selection function. Our
constraint on the cluster mass scale is consistent with recent results from the
Weighing the Giants program and the Canadian Cluster Comparison Project. It is
also consistent, at 1.34$\sigma$, with the value needed to reconcile the Planck
SZ cluster counts with Planck's base $\Lambda$CDM model fit to the primary
cosmic microwave background anisotropies.
