A Possible Supernova Remnant high above the Galactic Disk
  We present the analysis of three Suzaku observations of a bright arc in the
ROSAT All-Sky Survey 1/4 keV maps at $l \approx 247\degr$, $b \approx
-64\degr$. In particular, we have tested the hypothesis that the arc is the
edge of a bubble blown by an extraplanar supernova. One pointing direction is
near the brightest part of the arc, one is toward the interior of the
hypothesized bubble, and one is toward the bubble exterior. We fit spectral
models generated from 1-D hydrodynamical simulations of extraplanar supernova
remnants (SNRs) to the spectra. The spectra and the size of the arc
($\mathrm{radius} \approx 5\degr$) are reasonably well explained by a model in
which the arc is the bright edge of a $\sim$100,000-yr old SNR located
$\sim$1--2 kpc above the disk. The agreement between the model and the
observations can be improved if the metallicity of the X-ray--emitting gas is
$\sim$1/3 solar, which is plausible, as the dust which sequesters some metals
is unlikely to have been destroyed in the lifetime of the SNR. The width of the
arc is larger than that predicted by our SNR model; this discrepancy is also
seen with the Vela SNR, and may be due to the 1-D nature of our simulations. If
the arc is indeed the edge of an extraplanar SNR, this work supports the idea
that extraplanar supernovae contribute to the heating of the
$\sim$million-degree gas in the halo.
