Multi-frequency-synthesis and wide-field imaging with the EVLA

Broad-band receivers are used on radio interferometers to increase their continuum-imaging sensitivity. However, the interferometer sampling function, the sky brightness distribution, and the array-element response functions change with frequency. Imaging algorithms need to account for all these effects to reconstruct both the spatial and spectral structure of the sky brightness distribution over the wide fields-of-view allowed by the element response functions, while also achieving the full sensitivity offered by the large instantaneous bandwidths. In this talk, we will describe the algorithms used for wide-field wide-band imaging with the EVLA (Expanded Very Large Array), and show imaging results that demonstrate our current capabilities.