SNR 0506-680, Figure 6). In general, the line widths for C III are equal to or narrower than widths for O VI, consistent with a saturated C III ISM absorption (even stronger than in O VI) impacting the observed profile. The line profiles often give the impression of being cut off on the blue side, as if they are peeking out from under the overlying LMC absorption. We see only one example where substantial emission is seen blueward of the rest LMC (or SMC) wavelength, that being SNR 0536-706 (Figure 15), and in this case the blue wing of the line appears to be truncated by Milky Way O VI absorption. Since we are looking through the middle of each SNR, we are preferentially seeing redshifted emission from the back side of each SNR, while the front-side shell emission is typically absorbed or partially absorbed by MC and Milky Way ISM absorptions.

We now address the one object with detected C III and no O VI emission, SNR 0527-658 (Figure 9). It is conceivable that O VI emission is present in this object but just not at the location of the LWRS aperture, or that this object is dominated by 