Preprint typeset using L ATEX style emulateapj v. 10/09/06 GALAXY CLUSTERS DISCOVERED WITH A SUNYAEV-ZEL’DOVICH EFFECT SURVEY

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2009
• Subjects: Blanco; South Pole; South pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.244.4819; http://arxiv.org/pdf/0810.1578v1.pdf

The South Pole Telescope (SPT) is currently conducting a Sunyaev-Zel’dovich (SZ) effect survey over large areas of the southern sky, searching for massive galaxy clusters to high redshift. In this preliminary study, we focus on a 40 square-degree area targeted by the Blanco Cosmology Survey (BCS), which is centered roughly at right ascension 5 h 30 m, declination −53 ◦ (J2000). Over two seasons of observations, this entire region has been mapped by the SPT at 95 GHz, 150 GHz, and 225 GHz. We report the four most significant SPT detections of SZ clusters in this field, three of which were previously unknown and, therefore, represent the first galaxy clusters discovered with an SZ survey. The SZ clusters are detected as decrements with greater than 5σ significance in the high-sensitivity 150 GHz SPT map. The SZ spectrum of these sources is confirmed by detections of decrements at the corresponding locations in the 95 GHz SPT map and non-detections at those locations in the 225 GHz SPT map. Multiband optical images from the BCS survey demonstrate significant concentrations of similarly colored galaxies at the positions of the SZ detections. Photometric redshift estimates from the BCS data indicate that two of the clusters lie at moderate redshift (z ∼ 0.4) and two at high redshift (z � 0.8). One of the SZ detections was previously identified as a galaxy cluster using