After announcing in 2000 that two California telescope arrays would be united at a fresh site in the state’s Inyo mountains, the project’s university partners finally have the formal agreement and most of the money to go ahead with the merger (see Physics Today, January 2001, page 27). But before the Combined Array for Research in Millimeter-wave Astronomy is formed, a piggyback array of smaller telescopes will begin using the Sunyaev-Zel’dovich effect (SZE) to survey galaxy clusters.
Located at CARMA’s center, the subgroup of telescopes that make up the Sunyaev-Zel’dovich Array (SZA) will use the SZE to spot galaxy clusters by the distortions they cause in the cosmic microwave background. “Most of the scattering is from the intracluster medium—the soup between the galaxies,” says the University of Chicago’s John Carlstrom, SZA project leader. “It turns out [that the SZE] has this amazing property, that how well you...
