LoCuSS - Weak-lensing mass calibration of galaxy clusters

Nobuhiro Okabe, Graham P. Smith

Research output: Contribution to journalArticlepeer-review


We present weak-lensing mass measurements of 50 X-ray luminous galaxy clusters at $0.15\le z\le0.3$, based on high quality observations with Suprime-Cam mounted on the 8.2-m Subaru telescope. We pay close attention to possible systematic biases, aiming to control them at the $\lt4$ per cent level. The dominant source of systematic bias in weak-lensing measurements of the mass of individual galaxy clusters is contamination of background galaxy catalogues by faint cluster and foreground galaxies. We extend our conservative method for selecting background galaxies with $(V-i')$ colours redder than the red sequence of cluster members to use a colour-cut that depends on cluster-centric radius. This allows us to define background galaxy samples that suffer $\le1$ per cent contamination, and comprise $13$ galaxies per square arcminute. Thanks to the purity of our background galaxy catalogue, the largest systematic in our measurement is a shape measurement bias of $3$ per cent, that we measure using custom-made simulations that probe weak shears upto $g=0.3$. Our individual cluster mass and concentration measurements are in excellent agreement with predictions of the mass-concentration relation. Equally, our stacked shear profile is in excellent agreement with the Navarro Frenk and White profile. Our new LoCuSS mass measurements are consistent with the CCCP and CLASH surveys, and in tension with the Weighing the Giants (WtG) at $\sim2\sigma$ significance.
Original languageEnglish
JournalRoyal Astronomical Society. Monthly Notices
Publication statusPublished - Oct 2016

Bibliographical note

27 pages, 12 figures, 7 tables : submitted to MNRAS


  • astro-ph.CO


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