Discovery of kpc-scale line emission in barred galaxies, not linked to
  AGN or star formation
  We present an analysis of the optical line emission from nearby barred
galaxies, and in particular look at the radial range occupied by the bar. In
many cases this region is marked by what we term a 'star formation desert',
with a marked deficit of HII regions in optical narrow-band H-alpha imaging.
Here we present long-slit spectroscopy revealing that such regions do have line
emission, but that it is low-level, spatially smooth and almost ubiquitous. The
relative strengths of the H-alpha and the spectrally adjacent [NII] lines in
the regions are completely discrepant from those associated with star formation
regions, and more closely match expectations for 'LINER' regions. We quantify
the total line emission from these extended, kpc-scale regions, and determine
the spurious contribution it would make to the determined star formation rate
of these galaxies if interpreted as normal H-alpha emission. We concur with
previous studies that link this LINER emission to old stellar populations, e.g.
post-asymptotic giant branch stars, and propose these strongly-barred
early-type spirals as a prime location for further tests of such emission.
