Journal article

Weak-lensing mass calibration of the Sunyaev-Zel'dovich effect using APEX-SZ galaxy clusters

A Nagarajan, F Pacaud, M Sommer, M Klein, K Basu, F Bertoldi, AT Lee, PAR Ade, AN Bender, D Ferrusca, NW Halverson, C Horellou, BR Johnson, J Kennedy, R Kneissl, KM Menten, CL Reichardt, C Tucker, B Westbrook



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) Xray complete cluster sample, we calibrate the integrated Comptonization parameter, YSZ, to the weak-lensing derived total cluster mass, M500. We employ a novel Bayesian approach to account for the selection effects by jointly fitting both the..

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University of Melbourne Researchers


Awarded by Ministry of Economy and Technology (BMWi)

Awarded by Swedish Research Council

Awarded by National Science Foundation

Funding Acknowledgements

We thank Thomas Reiprich and Joe Mohr for useful discussions that has benefited this work. We acknowledge the help of Holger Israel in re-shaping part of this paper. We thank Jens Erler and Kevin Harrington for proof-reading an early draft of thismanuscript. We acknowledge the support and involvement of former graduate student Daniel Dahlin in the APEX-SZ Collaboration. We thank Reinhold Schaaf for providing support for the APEX-SZ data analysis software (BoA). We thank Hans Bohringer for sharing his knowledge that was helpful in the initial stages of target selection. ANwas supported in the initial few months period through a stipend from the International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the Universities of Bonn and Cologne. AN was later supported by the Ph.D. scholarship from Deutscher Akademischer Austauchdienst (DAAD). This work received support in part from the German Research Foundation (DFG) Transregio program TR33 'The Dark Universe'. FP acknowledges support by the German Aerospace Agency (DLR) with funds from the Ministry of Economy and Technology (BMWi) through grants 50 OR 1514 and 50 OR 1608. MK acknowledges the support of the Max Planck Gemeinschaft Faculty Fellowship program and the High Energy Group at MPE. MK also acknowledges the support of the DFG Cluster of Excellence 'Origin and Structure of the Universe'. CH acknowledges support from the Barbro Osher pro Suecia foundation and from the Swedish Research Council under grants 2006-3356 and 2009-4027. Work in theU.S. on the APEX-SZ instrument development and analysiswas supported by the National Science Foundation under grants AST-0138348 and AST-0709497.