Measurement of Galaxy Cluster Integrated Comptonization and Mass Scaling Relations with the South Pole Telescope
Gladders, M. D.; Rest, A.; Foley, R. J.; Zenteno, A.; Desai, S.; Hlavacek-Larrondo, J.; Bleem, L. E.; Stalder, B.; Stark, A. A.; Bayliss, M.; Stubbs, C. W.; George, E. M.; Reichardt, C. L.; Aird, K. A.; Benson, B. A.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Halverson, N. W.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Lueker, M.; Luong-Van, D.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mohr, J. J.; Montroy, T. E.; Padin, S.; Pryke, C.; Ruhl, J. E.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Staniszewski, Z.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.; Zahn, O.; Vikhlinin, A.; Saro, A.; McDonald, M.; Stanford, S. A.; Brodwin, M.; Forman, W. R.; Murray, S. S.; Gonzalez, A. H.; Marrone, D. P.; Ruel, J.; Story, K.; Bocquet, S.; Jones, C.; Clocchiatti, A.; Sayre, J. T.; Mocanu, L.; Saliwanchik, B. R.; Liu, J.; Dudley, J. P.; Cho, H. M.; Mantz, A.; Nurgaliev, D.; Patej, A.
United States, Germany, Chile, Canada
Abstract
We describe a method for measuring the integrated Comptonization (Y SZ) of clusters of galaxies from measurements of the Sunyaev-Zel'dovich (SZ) effect in multiple frequency bands and use this method to characterize a sample of galaxy clusters detected in the South Pole Telescope (SPT) data. We use a Markov Chain Monte Carlo method to fit a β-model source profile and integrate Y SZ within an angular aperture on the sky. In simulated observations of an SPT-like survey that include cosmic microwave background anisotropy, point sources, and atmospheric and instrumental noise at typical SPT-SZ survey levels, we show that we can accurately recover β-model parameters for inputted clusters. We measure Y SZ for simulated semi-analytic clusters and find that Y SZ is most accurately determined in an angular aperture comparable to the SPT beam size. We demonstrate the utility of this method to measure Y SZ and to constrain mass scaling relations using X-ray mass estimates for a sample of 18 galaxy clusters from the SPT-SZ survey. Measuring Y SZ within a 0.'75 radius aperture, we find an intrinsic log-normal scatter of 21% ± 11% in Y SZ at a fixed mass. Measuring Y SZ within a 0.3 Mpc projected radius (equivalent to 0.'75 at the survey median redshift z = 0.6), we find a scatter of 26% ± 9%. Prior to this study, the SPT observable found to have the lowest scatter with mass was cluster detection significance. We demonstrate, from both simulations and SPT observed clusters that Y SZ measured within an aperture comparable to the SPT beam size is equivalent, in terms of scatter with cluster mass, to SPT cluster detection significance.