Weak-lensing mass calibration of the Sunyaev-Zel'dovich effect using APEX-SZ galaxy clusters
Artikel i vetenskaplig tidskrift, 2019

The use of galaxy clusters as precision cosmological probes relies on an accurate determination of their masses. However, inferring the relationship between cluster mass and observables from direct observations is difficult and prone to sample selection biases. In this work, we use weak lensing as the best possible proxy for cluster mass to calibrate the Sunyaev-Zel'dovich (SZ) effect measurements from the APEX-SZ experiment. For a well-defined (ROSAT) X-ray complete cluster sample, we calibrate the integrated Comptonization parameter, Y-SZ, to the weak-lensing derived total cluster mass, M-500. We employ a novel Bayesian approach to account for the selection effects by jointly fitting both the SZ Comptonization, Y-SZ-M-500, and the X-ray luminosity, Lx-M-500, scaling relations. We also account for a possible correlation between the intrinsic (lognormal) scatter of L-x and Y-SZ at fixed mass. We find the corresponding correlation coefficient to be r = 0.47(-0.35)(+0.24), and at the current precision level our constraints on the scaling relations are consistent with previous works. For our APEX-SZ sample, we find that ignoring the covariance between the SZ and X-ray observables biases the normalization of the Y-SZ-M-500 scaling high by 1-2 sigma and the slope low by similar to 1 sigma, even when the SZ effect plays no role in the sample selection. We conclude that for higher precision data and larger cluster samples, as anticipated from on-going and near-future cluster cosmology experiments, similar biases (due to intrinsic covariances of cluster observables) in the scaling relations will dominate the cosmological error budget if not accounted for correctly.

galaxies: clusters: general galaxies: clusters: intracluster medium

cosmology: observations

methods: statistical

gravitational lensing: weak


A. Nagarajan

Universität zu Köln

Universität Bonn

F. Pacaud

Universität Bonn

M. Sommer

Universität Bonn

M. Klein


Ludwig-Maximilians-Universität München

K. Basu

Universität Bonn

F. Bertoldi

Universität Bonn

A. T. Lee

University of California at Berkeley

Lawrence Berkeley National Laboratory

P. A. R. Ade

Cardiff University

A. N. Bender

University of Colorado at Boulder

McGill University

D. Ferrusca

Instituto Nacional de Astrofísica, Óptica y Electrońica

N. W. Halverson

University of Colorado at Boulder

Cathy Horellou

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Extragalaktisk astrofysik

B. R. Johnson

Columbia University in the City of New York

J. Kennedy

McGill University

R. Kneissl

Atacama Large Millimeter-submillimeter Array (ALMA)

European Southern Observatory Santiago

K. M. Menten


C. L. Reichardt

University of Melbourne

C. Tucker

Cardiff University

B. Westbrook

University of California at Berkeley

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 488 2 1728-1759


Subatomär fysik

Astronomi, astrofysik och kosmologi

Sannolikhetsteori och statistik



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