MEASUREMENT OF GALAXY CLUSTER INTEGRATED COMPTONIZATION AND MASS SCALING RELATIONS WITH THE SOUTH POLE TELESCOPE
Author(s)McDonald, Michael A.
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We describe a method for measuring the integrated Comptonization (Y [subscript 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 [subscript 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 [subscript SZ] for simulated semi-analytic clusters and find that Y [subscript 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 [subscript 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 [subscript SZ] within a 0.'75 radius aperture, we find an intrinsic log-normal scatter of 21% ± 11% in Y [subscript SZ] at a fixed mass. Measuring Y [subscript 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 [subscript 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.
DepartmentMIT Kavli Institute for Astrophysics and Space Research
The Astrophysical Journal
Saliwanchik, B. R., T. E. Montroy, K. A. Aird, M. Bayliss, B. A. Benson, L. E. Bleem, S. Bocquet, et al. “MEASUREMENT OF GALAXY CLUSTER INTEGRATED COMPTONIZATION AND MASS SCALING RELATIONS WITH THE SOUTH POLE TELESCOPE.” The Astrophysical Journal 799, no. 2 (January 22, 2015): 137. © 2015 The American Astronomical Society
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