The DEM L 316 system contains two shells , both with the characteristic signatures of supernova remnants ( SNRs ) .
We analyze Chandra and XMM-Newton data for DEM L 316 , investigating its spatial and spectral X-ray features .
Our Chandra observations resolve the structure of the northeastern SNR ( Shell A ) as a bright inner ring and a set of “ arcs ” surrounded by fainter diffuse emission .
The spectrum is well fit by a thermal plasma model with temperature \sim 1.4 keV ; we do not find significant spectral differences for different regions of this SNR .
The southwestern SNR ( Shell B ) exhibits an irregular X-ray outline , with a brighter interior ring of emission including a bright knot of emission .
Overall the emission of the SNR is well described by a thermal plasma of temperature \sim 0.6 keV .
The Bright Knot , however , is spectrally distinct from the rest of the SNR , requiring the addition of a high-energy spectral component consistent with a power-law spectrum of photon index 1.6–1.8 .

We confirm the findings of Nishiuchi et al .
( 19 ) that the spectra of these shells are notably different , with Shell A requiring a high iron abundance for a good spectral fit , implying a Type Ia origin .
We further explicitly compare abundance ratios to model predictions for Type Ia and Type II supernovae .
The low ratios for Shell A ( O/Fe of 1.5 and Ne/Fe of 0.2 ) and the high ratios for Shell B ( O/Fe of 30–130 and Ne/Fe of 8–16 ) are consistent with Type Ia and Type II origins , respectively .
The difference between the SNR progenitor types casts some doubt on the suggestion that these SNRs are interacting with one another .