We present a catalog of 224Â 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 \sim 18 \mu \mathrm { K } _ { \mathrm { CMB } } -arcmin at 150 GHz ; 550 deg ^ { 2 } of it was also mapped to \sim 44 \mu \mathrm { K } _ { \mathrm { CMB } } -arcmin at 95 GHz .
Based on optical imaging of all candidates and near-infrared imaging of the majority of candidates , we have found optical and/or infrared counterparts for 158Â clusters .
Of these , 135 were first identified as clusters in SPT data , including 117Â 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 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 } \approx 5 \times 10 ^ { 14 } M _ { \odot } h _ { 70 } ^ { -1 } at z \gtrsim 0.6 .
There are 121 candidates detected at signal-to-noise 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 .
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 \sum m _ { \nu } < 0.38 eV ( 95 % CL ) .
For a spatially flat wCDMÂ cosmological model , the addition of this catalog to the CMB+BAO+H _ { 0 } +SNe results yields \sigma _ { 8 } = 0.807 \pm 0.027 and w = -1.010 \pm 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 .
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 .