SOURCE COUNTS FOR THE THERMAL AND KINETIC SUNYAEV-ZELDOVICH EFFECTS IN CLUSTERS OF GALAXIES

The growing possibility of observing the thermal and kinetic (Doppler) Sunyaev-Zel'dovich (SZ) sources and their contribution to extragalact ic background fluctuations from ground-based and space experiments, sc heduled for the next decade, makes it timely to predict source counts as a function of flux. We present calculations of SZ source counts for unresolved cluster of galaxies, including the Doppler effect, and pre dictions for millimeter and submillimeter wavelengths, not included in previous works. Calculations show that future high sensitivity experi ments could observe many thermal and kinetic SZ effect sources in all- sky surveys. The measurement of the kinetic effect on hundreds of clus ters could yield precious information on the large scale velocity fiel d of the Universe. We found a mean Comptonization parameter of (y) ove r bar similar to 1.2 . 10(-6), compatible with the COBE limit. We also calculate the contribution of these SZ effect sources to the rms temp erature fluctuations relative to the Cosmic Microwave Background and f ind that it cannot be neglected at small angular scales at a sensitivi ty level delta T/T similar to 10(-6).