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 \arcdeg , b \approx - 64 \arcdeg .
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 \arcdeg ) 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 .