Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 1, 2011 | Published
Journal Article Open

X-Ray Properties of the First Sunyaev-Zel'dovich Effect Selected Galaxy Cluster Sample from the South Pole Telescope

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 deg^2 of sky surveyed by the South Pole Telescope (SPT). Using X-ray observations with Chandra and XMM-Newton, we estimate the temperature, T_X, and mass, M_g, of the intracluster medium within r_500 for each cluster. From these, we calculate Y_X = M_(g)T_X and estimate the total cluster mass using an M_(500)-Y_X 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)-Y_X relation and find a normalization of 0.82 ± 0.07, marginally consistent with the predicted ratio of Y_(SZ)/Y_X = 0.91 ± 0.01 that would be expected from the density and temperature models used in this work. Using the Y_X-derived mass estimates, we fit a Y_(SZ)-M_500 relation and find a slope consistent with the self-similar expectation of Y_(SZ) ∝ M^(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.

Additional Information

© 2011 American Astronomical Society. Received 2010 June 17; accepted 2011 May 23; published 2011 August 11. The South Pole Telescope is supported by the National Science Foundation through grant ANT-0638937. Partial support is also provided by the NSF Physics Frontier Center grant PHY-0114422 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation, and the Gordon and Betty Moore Foundation. Support for X-ray analysis was provided by NASA through Chandra Award Number GO0-11143 issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. Additional support is provided by NASA through XMM-Newton Award NNX09AQ04G and Chandra Award AR0-11015A. K. Andersson is supported in part by NASA through SAO Award Number 2834-MIT-SAO-4018 issued by the Chandra X-ray Observatory Center. The Munich group is supported by the DFG through TRR33 "The Dark Universe" and the Excellence Cluster Universe. The McGill group acknowledges funding from the National Sciences and Engineering Research Council of Canada, the Quebec Fonds de recherche sur la nature et les technologies and the Canadian Institute for Advanced Research. The following individuals acknowledge additional support: B. Stalder from the Brinson Foundation, B. Benson from a KICP Fellowship, R. Foley from a Clay Fellowship, D. Marrone from Hubble Fellowship grant HF-51259.01-A, N. W. Halverson acknowledges support from an Alfred P. Sloan Research Fellowship. M. Brodwin from the Keck Foundation, and A. T. Lee from the Miller Institute for Basic Research in Science, University of California Berkeley. Facilities: CXO (ACIS), XMM (EPIC), Blanco (MOSAIC II), Magellan:Baade (IMACS), Magellan:Clay (LDSS2)

Attached Files

Published - Andersson2011p15683Astrophys_J.pdf

Files

Andersson2011p15683Astrophys_J.pdf
Files (6.1 MB)
Name Size Download all
md5:b47e92bcf8080a9b8b041105f9f1feee
6.1 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 24, 2023