X-Ray Properties of the First Sunyaev-Zel'dovich Effect Selected Galaxy Cluster Sample from the South Pole Telescope
Gladders, M. D.; Ade, P. A. R.; Rest, A.; Foley, R. J.; Zenteno, A.; Desai, S.; Yang, Y.; Bleem, L. E.; Stalder, B.; Stark, A. A.; 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.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mohr, J. J.; Montroy, T. E.; Padin, S.; Plagge, T.; Pryke, C.; Ruhl, J. E.; Schaffer, K. K.; Shaw, L.; Shirokoff, E.; Spieler, H. G.; Staniszewski, Z.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.; Zahn, O.; Vikhlinin, A.; Brodwin, M.; Forman, W. R.; Murray, S. S.; Marrone, D. P.; High, F. W.; Ruel, J.; Jones, C.; Song, J.; Andersson, K.; Armstrong, B.; Bautz, M.; Dudley, J. P.; Garmire, G.; Joy, M.
United States, Germany, United Kingdom, Canada, Russia
Abstract
We present results of X-ray observations of a sample of 15 clusters selected via their imprint on the cosmic microwave background from the thermal Sunyaev-Zel'dovich (SZ) effect. These clusters are a subset of the first SZ-selected cluster catalog, obtained from observations of 178 deg2 of sky surveyed by the South Pole Telescope (SPT). Using X-ray observations with Chandra and XMM-Newton, we estimate the temperature, TX , and mass, Mg , of the intracluster medium within r 500 for each cluster. From these, we calculate YX = MgTX and estimate the total cluster mass using an M 500-YX scaling relation measured from previous X-ray studies. The integrated Comptonization, Y SZ, is derived from the SZ measurements, using additional information from the X-ray-measured gas density profiles and a universal temperature profile. We calculate scaling relations between the X-ray and SZ observables and find results generally consistent with other measurements and the expectations from simple self-similar behavior. Specifically, we fit a Y SZ-YX relation and find a normalization of 0.82 ± 0.07, marginally consistent with the predicted ratio of Y SZ/YX = 0.91 ± 0.01 that would be expected from the density and temperature models used in this work. Using the YX -derived mass estimates, we fit a Y SZ-M 500 relation and find a slope consistent with the self-similar expectation of Y SZvpropM 5/3 with a normalization consistent with predictions from other X-ray studies. We find that the SZ mass estimates, derived from cosmological simulations of the SPT survey, are lower by a factor of 0.78 ± 0.06 relative to the X-ray mass estimates. This offset is at a level of 1.3σ when considering the ~15% systematic uncertainty for the simulation-based SZ masses. Overall, the X-ray measurements confirm that the scaling relations of the SZ-selected clusters are consistent with the properties of other X-ray-selected samples of massive clusters, even allowing for the broad redshift range (0.29 < z < 1.08) of the sample.