The Mipsgal View of Supernova Remnants in the Galactic Plane
  We report the detection of Galactic supernova remnants (SNRs) in the
mid-infrared (at 24 and 70 {\mu}m), in the coordinate ranges 10 < l < 65 deg
and 285 < l < 350 deg, |b| < 1 deg, using the Multiband Imaging Photometer
(MIPS) aboard the Spitzer Space Telescope. We search for infrared counterparts
to SNRs in Green's catalog and identify 39 out of 121, i.e., a detection rate
of about 32%. Such a relatively low detection fraction is mainly due to
confusion with nearby foreground/background sources and diffuse emission. The
SNRs in our sample show a linear trend in [F8/F24] versus [F70/F24]. We compare
their infrared fluxes with their corresponding radio flux at 1.4 GHz and find
that most remnants have ratios of 70 {\mu}m to 1.4 GHz characteristic of SNRs
(with the exception of a few which have ratios closer to those of H II
regions). Furthermore, we retrieve a slope close to unity when correlating
infrared (24 and 70 {\mu}m) with 1.4 GHz emission. Our survey is more
successful in detecting remnants with bright X-ray emission, which we find is
well correlated with the 24 {\mu}m morphology. Moreover, by comparing the power
emitted in X-ray, infrared and radio, we conclude that the energy released in
the infrared is comparable to the cooling in the X-ray range.
