  The radio continuum emission from the Galaxy has a rich mix of thermal and
non-thermal emission. This very richness makes their interpretation challenging
since the low radio opacity means that a radio image represents the sum of all
emission regions along the line-of-sight. These challenges make the existing
narrow-band radio surveys of the Galactic plane difficult to interpret: e.g. a
small region of emission might be a supernova remnant (SNR) or an HII region,
or a complex combination of both. Instantaneous wide bandwidth radio
observations in combination with the capability for high resolution spectral
index mapping, can be directly used to disentangle these effects.
  Here we demonstrate simultaneous continuum and spectral index imaging
capability at the full continuum sensitivity and resolution using newly
developed wide-band wide-field imaging algorithms. Observations were done in
the L- and C-Band with a total bandwidth of 1 and 2 GHz respectively. We
present preliminary results in the form of a full-field continuum image
covering the wide-band sensitivity pattern of the EVLA centered on a large but
poorly studied SNR (G55.7+3.4) and relatively narrower field continuum and
spectral index maps of three fields containing SNR and diffused thermal
emission. We demonstrate that spatially resolved spectral index maps
differentiates regions with emission of different physical origin (spectral
index variation across composite SNRs and separation of thermal and non-thermal
emission), superimposed along the line of sight. The wide-field image centered
on the SNR G55.7+3.4 also demonstrates the excellent wide-field wide-band
imaging capability of the EVLA.
