Far-ultraviolet and Hα spectroscopy of SNR 0057-7226 in the small magellanic cloud H II region N66

N66/NGC 346 is the largest and brightest H II region in the Small Magellanic Cloud and contains at least one known supernova remnant, SNR 0057-7226. Optical emission from the remnant is overwhelmed by the bright photoionized emission from the nebula, but the remnant has been detected by way of far-ultraviolet absorption (FUV) lines. Here we present data from the Far-Ultraviolet Spectroscopic Explorer (FUSE) satellite showing strong O VI and C III emission from a position at the edge of SNR 0057-7226. We also present high-resolution, long-slit Hα spectra across N66, showing high- and low-velocity emission corresponding closely to the X-ray boundaries of the supernova remnant. We use these FUV and optical data to determine the physical parameters of the shock and interaction geometry with N66. We find that ionizing photons from the many massive cluster stars nearby likely affect the ionization balance in the postshock gas, hindering the production of lower ionization and neutral species. We discuss the importance and inherent difficulty of searching for supernova remnants in or near bright H II regions and suggest that the far ultraviolet provides a viable means to discover and study such remnants.