Measuring small-scale anisotropy in the Cosmic Microwave Background with the Sunyaev-Zel'dovich Array.

by Matthew K. Sharp

Using the Sunyaev Zel'dovich Array (SZA), an eight-element interferometer observing at 30 GHz, we make a measurement of the fluctuation power spectrum of Cosmic Microwave Background (CMB) anisotropy on angular scales corresponding to several arcminutes. Within this range, we expect the primary CMB to be greatly damped and dominated by secondary contributions, especially the Sunyaev Zel'dovich Effect from intermediate-mass galaxy clusters.;We measure 93 +/- 66microK2 of power in 44 fields with the SZA. We attribute 30microK2 of this power to primary CMB, and a further ∼ 5 -- 10microK2 to galactic dust grains that are spinning. We believe that we have accounted for all power contributed by radio point sources. The remaining 60 +/- 66microK 2 of power we attribute to the Sunyaev Zel'dovich Effect, consistent with simulations of structure with sigma8=0.8. While previous measurements have shown some tension with such a low value of sigma 8, we see no such tension.;We introduce the measurement with a brief description of sigma 8 and its role in the standard cosmological model, and then describe the SZA and our observations. The analysis that we have conducted is described in detail, as well as our interpretation of the results.

132 pages, NOOK Study eTextbook