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 February 1, 2013 | Published
Journal Article Open

Galaxy Clusters Discovered via the Sunyaev-Zel'dovich Effect in the First 720 Square Degrees of the South Pole Telescope Survey

Abstract

We present a catalog of galaxy cluster candidates, selected through their Sunyaev-Zel'dovich (SZ) effect signature in the first 720 deg^2 of the South Pole Telescope (SPT) survey. This area was mapped with the SPT in the 2008 and 2009 austral winters to a depth of ~18 μK_(CMB)-arcmin at 150 GHz; 550 deg2 of it was also mapped to ~44 μK_(CMB)-arcmin at 95 GHz. Based on optical imaging of all 224 candidates and near-infrared imaging of the majority of candidates, we have found optical and/or infrared counterparts for 158, which we then classify as confirmed galaxy clusters. Of these 158 clusters, 135 were first identified as clusters in SPT data, including 117 new discoveries reported in this work. This catalog triples the number of confirmed galaxy clusters discovered through the SZ effect. We report photometrically derived (and in some cases spectroscopic) redshifts for confirmed clusters and redshift lower limits for the remaining candidates. The catalog extends to high redshift with a median redshift of z = 0.55 and maximum confirmed redshift of z = 1.37. Forty-five of the clusters have counterparts in the ROSAT bright or faint source catalogs from which we estimate X-ray fluxes. Based on simulations, we expect the catalog to be nearly 100% complete above M_(500) ≈ 5 × 10^(14) M_☉ h^(–1) 70 at z ≳0.6. There are 121 candidates detected at signal-to-noise ratio greater than five, at which the catalog purity is measured to be 95%. From this high-purity subsample, we exclude the z < 0.3 clusters and use the remaining 100 candidates to improve cosmological constraints following the method presented by Benson et al. Adding the cluster data to CMB + BAO + H_0 data leads to a preference for non-zero neutrino masses while only slightly reducing the upper limit on the sum of neutrino masses to ∑m_ν < 0.38 eV (95% CL). For a spatially flat wCDM cosmological model, the addition of this catalog to the CMB + BAO + H_0 + SNe results yields σ_8 = 0.807 ± 0.027 and w = –1.010 ± 0.058, improving the constraints on these parameters by a factor of 1.4 and 1.3, respectively. The larger cluster catalog presented in this work leads to slight improvements in cosmological constraints from those presented by Benson et al. These cosmological constraints are currently limited by uncertainty in the cluster mass calibration, not the size or quality of the cluster catalog. A multi-wavelength observation program to improve the cluster mass calibration will make it possible to realize the full potential of the final 2500 deg^2 SPT cluster catalog to constrain cosmology.

Additional Information

© 2013 American Astronomical Society. Received 2012 March 26; accepted 2012 December 10; published 2013 January 16. The South Pole Telescope program 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. Galaxy cluster research at Harvard is supported by NSF grant AST-1009012. Galaxy cluster research at SAO is supported in part by NSF grants AST-1009649 and MRI-0723073. The McGill group acknowledges funding from the National Sciences and Engineering Research Council of Canada, Canada Research Chairs program, and the Canadian Institute for Advanced Research. X-ray research at the CfA is supported through NASA Contract NAS 8-03060. This work is based in part on observations made with the Spitzer Space Telescope,which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. The Munich group acknowledges support from the Excellence Cluster Universe and the DFG research program TR33. R.J.F. is supported by a Clay Fellowship. B.A.B is supported by a KICP Fellowship, M. Bautz acknowledges support from contract 2834-MIT-SAO-4018 from the Pennsylvania State University to the Massachusetts Institute of Technology. M. D. acknowledges support from an Alfred P. Sloan Research Fellowship, W. F. and C. J. acknowledge support from the Smithsonian Institution, and B.S. acknowledges support from the Brinson Foundation. Support for X-ray analysis was provided by NASA through Chandra Award Numbers 12800071, 12800088, and G02-13006A issued by the ChandraX-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. Optical imaging data from the Blanco 4 m at Cerro Tololo Inter-American Observatories (programs 2005B-0043, 2009B-0400, 2010A-0441, and 2010B-0598) and spectroscopic observations from VLT programs 086.A-0741 and 286.A-5021 and Gemini program GS-2009B-Q-16 were included in this work. Additional data were obtained with the 6.5 m Magellan Telescopes located at the Las Campanas Observatory, Chile. We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis (LAMBDA). Support for LAMBDA is provided by the NASA Office of Space Science. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France, and the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Facilities: Blanco (MOSAIC, NEWFIRM), CXO (ACIS), Gemini:South (GMOS), Magellan:Baade (IMACS), Magellan: Clay (LDSS3), Spitzer (IRAC), SPT, Swope (CCD), XMM (EPIC)

Attached Files

Published - 0004-637X_763_2_127.pdf

Files

0004-637X_763_2_127.pdf
Files (813.0 kB)
Name Size Download all
md5:d2f0030013758c7745775b3b573daee4
813.0 kB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023