A search for periodic variations of solar radio emission at 3.7-and 11.1-cm wavelengths

A search has been made for periodic time variations in the emission of quiet solar regions with the NRAO three-element interferometer at 3.7 and 11.1cm. The visibility function of a source as obtained with a tracking interferometer is an implicit function of time, because of projected baseline changes, and therefore only observations taken when the baseline changes vary slowly with time have been used. The visibility function shows significant time variations, but a power-spectrum analysis of the data revealed no unique periodicity. The estimated size of the time-varying elements is 2 min.5+-0 min.2 arc at 3.7cm and 7 min.3+-0 min.4 arc at 11.1cm. (author)