MICROWAVE BACKGROUND FLUCTUATIONS DUE TO THE SUNYAEV-ZELDOVICH EFFECTIN PANCAKES

We calculate distortions in the microwave background radiation from th e Sunyaev-Zel'dovich effect, produced by hot gas in large (similar to 100 Mpc) pancakes. The large-scale distribution of the pancakes is tak en to be that of a Voronoi foam. Fluctuations for this scenario are es timated to be on the order of Delta T/T similar to 10(-5). Using compu ter simulations, we produce several 32 degrees x32 degrees images with 0 degrees 25 resolution. These images show characteristic linear feat ures produced when a pancake is viewed nearly edge-on. By calculating the two-point and the degenerate three-point correlation functions, we are able to statistically detect such non-Gaussian features even in t he presence of a relatively large amount of Gaussian noise. The degene rate three-point correlation function is found to be particularly usef ul since it is insensitive to correlated Gaussian noise. We also smoot h our data over a 7 degrees FWHM Gaussian window to simulate the COBE observations. We find that under such low-resolution conditions, the f eatures are highly suppressed.