Spatial coherence in a scatter-broadened image-observations of 3C279 close to the sun

Abstract

Using the VLA, the IPS scattered disk of 3C279 has been imaged close to the sun with high spatial and temporal resolution. The resulting images have speckles, similar to those seen in short-exposure optical photographs of the seeing disk. A test for coherence in the scattered radiation is described, and it is shown that, under suitable observing conditions, the observed radiation is indeed spatially coherent.