The Sunyaev-Zeldovich Effect as Microwave Foreground and Probe of\n Cosmology

The Sunyaev-Zel'dovich (SZ) effect from clusters of galaxies should yield a\nsignificant signal in cosmic microwave background(CMB) experiments at small\nangular scales ($\\ell \\ga 1000$). Experiments with sufficient frequency\ncoverage should be able to remove much of this signal in order to recover the\nprimary anisotropy. The SZ signal is interesting in its own right; the\namplitude and angular dependence are sensitive to both cosmology and the\nevolution of the gas. Combining CMB measurements with planned non-targeted SZ\nsurveys could isolate the cosmological effects, providing CMB experiments with\na low-redshift test of cosmology as a consistency check. Improvements in the\ndetermination of the angular diameter distance as a function of redshift from\nSZ and X-ray observations of a large sample of clusters will also provide a\nprobe of cosmology.\n