We report a Far Ultraviolet Spectroscopic Explorer satellite observation ofthe supernova remnant N49 in the Large Magellanic Cloud, covering the 905 --1187 A spectral region. A 30'' square aperture was used, resulting in avelocity resolution of ~100 km/s. The purpose of the observation was to examineseveral bright emission lines expected from earlier work and to demonstratediffuse source sensitivity by searching for faint lines never seen previouslyin extragalactic supernova remnant UV spectra. Both goals were accomplished.Strong emission lines of O VI 1031.9 A, 1037.6 A and C III 977.0 A were seen,Doppler broadened to +/- 225 km/s and with centroids red-shifted to 350 km/s,consistent with the LMC. Superimposed on the emission lines are absorptions byC III and O VI 1031.9 at +260 km/s, which are attributed to warm and hot gas(respectively) in the LMC. The O VI 1037.6 A line is more severely affected byoverlying interstellar and H2 absorption from both the LMC and our galaxy. NIII 989.8 A is not seen, but models indicate overlying absorption severelyattenuates this line. A number of faint lines from hot gas have also beendetected, many of which have never been seen in an extragalactic supernovaremnant spectrum.
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机译:我们报告了大麦哲伦星云中超新星残留N49的远紫外光谱资源管理器卫星观测,覆盖了905 --1187 A光谱区域。使用的是30英寸见方的孔径,其速度分辨率约为100 km / s。观察的目的是检查早期工作中预期的几条明亮发射线,并通过寻找银河系超新星残余紫外线光谱中以前从未见过的微弱线来证明扩散源敏感性。这两个目标都实现了。观察到强的O VI 1031.9 A,1037.6 A和C III 977.0 A发射线,多普勒展宽到+/- 225 km / s,质心红移到350 km / s,与LMC一致。排放线上叠加的是C III和O VI 1031.9在+260 km / s处的吸收,这分别归因于LMC中的热气和热气。 OLM 1037.6 A线受到LMC和银河系中星际和H2的过度吸收的严重影响。 NIII 989.8 A未见,但模型表明过度吸收会严重削弱该谱线。还检测到许多来自热气体的微弱线,其中许多从未在银河系超新星残留光谱中见过。
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