Imaging Microwave Spectroscopy of the Sun with the Owens Valley Solar Array

9311416 Gary The grant supplies major funding for the analysis of radio data from the Owens Valley Solar Array, a solar-dedicated array capable of two-dimensional mapping of solar flares and active regions at a wide range of microwave frequencies. The array has recently been upgraded to 5 antennas, giving 10 baselines at each observing frequency. By combining UV coverage in closely spaced frequencies, we obtain snapshot maps at a number of frequency bands, or for steady emission the project obtains rotational synthesis maps at up to 45 frequencies. The combination of spectral and imaging capabilities makes the array a unique, powerful instrument for studying the physical conditions in active regions, and the spatial and temporal development of mildly relativistic electrons accelerated in flares. During the period covered by this proposal, observations made jointly with currently operating spacecraft (Yohkoh and CGRO) will be of added importance. Early results prove that the instrument fulfills its design goals. ***