The Sunyaev-Zel'dovich Array (SZA) is an eight-element interferometric array of 3.5 meter telescopes designed to observe the Sunyaev-Zel'dovich effect in clusters of galaxies at 30 GHz and 90 GHz. This instrument is useful both for targeted cluster observations and for blind surveys, allowing us to learn about cosmological parameters from a unique look at the history of cluster formation in the early universe. It also allows us to study cluster physics at redshifts inaccessible to other types of observations.
The Sunyaev-Zel'dovich Array now operates as part of the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Its initial goal of surveying the Cosmic Microwave Background was completed in 2007, and now the array is used primarily to characterize clusters via the Sunyaev Zel'dovich effect.