Weak-lensing mass calibration of the Sunyaev-Zel'dovich effect using APEX-SZ galaxy clusters
Journal article, 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
Author
A. Nagarajan
University of Cologne
University of Bonn
F. Pacaud
University of Bonn
M. Sommer
University of Bonn
M. Klein
Max Planck Society
Ludwig Maximilian University of Munich (LMU)
K. Basu
University of Bonn
F. Bertoldi
University of 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
National Institute of Astrophysics, Optics and Electronics
N. W. Halverson
University of Colorado at Boulder
Cathy Horellou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
B. R. Johnson
Columbia University
J. Kennedy
McGill University
R. Kneissl
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
K. M. Menten
Max Planck Society
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 1728-1759Subject Categories
Subatomic Physics
Astronomy, Astrophysics and Cosmology
Probability Theory and Statistics
DOI
10.1093/mnras/sty1904