A measurement of the kinetic Sunyaev-Zel'dovich signal toward MACS J0717.5+3745

Journal Article · Wed Nov 20 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/1/52· OSTI ID:22342016

Sayers, J.; Mroczkowski, T.; Zemcov, M.; Bock, J.; Czakon, N. G.; Golwala, S. R.; Siegel, S. ^[1]; Korngut, P. M.; Moustakas, L. ^[2]; Bulbul, E. ^[3]; Egami, E.; Rawle, T. D.; Rex, M. ^[4]; Koch, P. M.; Lin, K. -Y. ^[5]; Mantz, A. ^[6]; Molnar, S. M. ^[7]; Pierpaoli, E.; Shitanishi, J. A. ^[8]; others, and

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1. Division of Physics, Math, and Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
2. Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)
3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
4. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
5. Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China)
6. Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
7. LeCosPA Center, National Taiwan University, Taipei 10617, Taiwan (China)
8. Department of Physics and Astronomy, University of Southern California, 3620 McClintock Avenue, Los Angeles, CA 90089 (United States)

We report our analysis of MACS J0717.5+3745 using 140 and 268 GHz Bolocam data collected at the Caltech Submillimeter Observatory. We detect extended Sunyaev-Zel'dovich (SZ) effect signal at high significance in both Bolocam bands, and we employ Herschel-SPIRE observations to subtract the signal from dusty background galaxies in the 268 GHz data. We constrain the two-band SZ surface brightness toward two of the sub-clusters of MACS J0717.5+3745: the main sub-cluster (named C), and a sub-cluster identified in spectroscopic optical data to have a line-of-sight velocity of +3200 km s{sup –1} (named B). We determine the surface brightness in two separate ways: via fits of parametric models and via direct integration of the images. For both sub-clusters, we find consistent surface brightnesses from both analysis methods. We constrain spectral templates consisting of relativistically corrected thermal and kinetic SZ signals, using a jointly-derived electron temperature from Chandra and XMM-Newton under the assumption that each sub-cluster is isothermal. The data show no evidence for a kinetic SZ signal toward sub-cluster C, but they do indicate a significant kinetic SZ signal toward sub-cluster B. The model-derived surface brightnesses for sub-cluster B yield a best-fit, line-of-sight velocity of v{sub z} = +3450 ± 900 km s{sup –1}, with (1 – Prob[v{sub z} ≥ 0]) = 1.3 × 10{sup –5} (4.2σ away from 0 for a Gaussian distribution). The directly integrated sub-cluster B SZ surface brightnesses provide a best-fit v{sub z} = +2550 ± 1050 km s{sup –1}, with (1 – Prob[v{sub z} ≥ 0]) = 2.2 × 10{sup –3} (2.9σ).

• OSTI ID: 22342016
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 778; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BRIGHTNESS
ELECTRON TEMPERATURE
GALAXIES
GALAXY CLUSTERS
GAUSS FUNCTION
GHZ RANGE
SIGNALS
SURFACES
VELOCITY