GALAXY CLUSTERS DISCOVERED WITH A SUNYAEV-ZEL'DOVICH EFFECT SURVEY

Journal Article · Mon Aug 10 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/701/1/32; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21313715

Staniszewski, Z ^[1]; Ade, P A. R. ^[2]; Aird, K A; Hrubes, J D ^[3]; Benson, B A; Cho, H -M; Holzapfel, W L; Lee, A T ^[4]; Bleem, L E; Carlstrom, J E; Chang, C L; Crawford, T M; Crites, A T; Keisler, R ^[5]; De Haan, T; Dobbs, M A; Holder, G P; Lanting, T M ^[6]; Halverson, N W ^[7]

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1. Physics Department, Case Western Reserve University, Cleveland, OH 44106 (United States)
2. Department of Physics and Astronomy, Cardiff University, CF24 3YB (United Kingdom)
3. University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
4. Department of Physics, University of California, Berkeley, CA 94720 (United States)
5. Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
6. Department of Physics, McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8 (Canada)
7. Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States)

The South Pole Telescope (SPT) is 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 deg{sup 2} area targeted by the Blanco Cosmology Survey (BCS), which is centered roughly at right ascension 5{sup h}30{sup m}, declination -53 deg. (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 5{sigma} 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 nondetections 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 {approx} 0.4) and two at high redshift (z {approx}> 0.8). One of the SZ detections was previously identified as a galaxy cluster in the optical as part of the Abell supplementary southern cluster catalog and in the X-ray using data from the ROSAT All-Sky Survey (RASS). Potential RASS counterparts (not previously identified as clusters) are also found for two of the new discoveries. These first four galaxy clusters are the most significant SZ detections from a subset of the ongoing SPT survey. As such, they serve as a demonstration that SZ surveys, and the SPT in particular, can be an effective means for finding galaxy clusters.

• OSTI ID: 21313715
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 701; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
COSMOLOGY
GALAXIES
GALAXY CLUSTERS
GHZ RANGE
RED SHIFT
RELICT RADIATION
TELESCOPES
X RADIATION