We present an HST/ACS weak gravitational lensing analysis of 13 massive high-redshift ( z _ { \mathrm { median } } = 0.88 ) galaxy clusters discovered in the South Pole Telescope ( SPT ) Sunyaev-Zel ’ dovich Survey .
This study is part of a larger campaign that aims to robustly calibrate mass-observable scaling relations over a wide range in redshift to enable improved cosmological constraints from the SPT cluster sample .
We introduce new strategies to ensure that systematics in the lensing analysis do not degrade constraints on cluster scaling relations significantly .
First , we efficiently remove cluster members from the source sample by selecting very blue galaxies in V - I colour .
Our estimate of the source redshift distribution is based on CANDELS data , where we carefully mimic the source selection criteria of the cluster fields .
We apply a statistical correction for systematic photometric redshift errors as derived from Hubble Ultra Deep Field data and verified through spatial cross-correlations .
We account for the impact of lensing magnification on the source redshift distribution , finding that this is particularly relevant for shallower surveys .
Finally , we account for biases in the mass modelling caused by miscentring and uncertainties in the concentration–mass relation using simulations .
In combination with temperature estimates from Chandra we constrain the normalisation of the mass–temperature scaling relation \ln \left ( E ( z ) M _ { \mathrm { 500 c } } / 10 ^ { 14 } \mathrm { M } _ { \odot } \right ) = A + 1.5 \ln \left ( % kT / 7.2 \mathrm { keV } \right ) to A = 1.81 ^ { +0.24 } _ { -0.14 } ( \mathrm { stat . } ) { \pm } 0.09 ( \mathrm { sys . } ) , consistent with self-similar redshift evolution when compared to lower redshift samples .
Additionally , the lensing data constrain the average concentration of the clusters to c _ { \mathrm { 200 c } } = 5.6 ^ { +3.7 } _ { -1.8 } .