Resonance-line scattering in supernova remnant shocks

We present a three-dimensional radiative transfer model to examine the effe cts of resonance-line scattering in the postshock flow behind a nonradiativ e supernova remnant shock. For a rippled shock front viewed edge-on, line s cattering significantly reduces the observed flux of C IV lambda 1549 and N V lambda 1240, two important diagnostic lines in the ultraviolet spectra o f supernova remnants. The correction factor (defined to be the ratio of the line flux that would be observed neglecting scattering to the actual obser ved line flux) is a function of position within the filament. For sufficien tly large regions that include crisp edges as well as more diffuse regions of the filament structure, the C IV and N V correction factors are between about 1.5 and 3.5 (and the C IV correction factor is invariably larger than the N V correction factor). The correction factors have a larger range whe n smaller regions are considered. The C IV correction factor is about 6 at the filament edges, while the N V correction factor is about 4. These simul ations of resonance-line scattering will be useful for the analysis of supe rnova remnant shock spectra.