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P. Treuthardt (U. Ala), W.C. Keel (U. Ala.), J. Holberg (U. Ariz./LPL), C. Steidel (Caltech)
We present FUSE spectra of star-forming regions in nearby galaxies, with emphasis on comparison with high-redshift systems. The spectra include four H II regions in M33 - NGC 604, 595, 598, and 592 - plus NGC 5461 in M101 and the starburst nucleus in NGC 7714. These span a metallicity range of [O/H]= 8.4--8.7. The entire spectral morphology changes noticeably across even this modest abundance range, with likely contributions from blending of stellar lines and from interstellar absorption. The three faintest regions in M33 have nearly identical spectra, while NGC 604 has slightly different contrast in the high-order Lyman lines, perhaps associated with the level of very recent star formation there. The high signal-to-noise obtained for NGC 604 helps interpret the other spectra, especially with regard to line blends. We compare the far-UV range in these nearby star-forming regions to a composite spectrum of Lyman-break galaxies at z \approx 3, combined to avoid the effects of individual Lyman \alpha forest absorbers. A major difference appears around the prominent P Cygni features, especially O VI and N III, while the continuum shape and Lyman absorption are similar. These features are produced in the stellar winds whose driving is very sensitive to composition. This is consistent with abundances substantially below solar in the high-redshift objects, a conclusion reinforcing estimates from broad-band continuum shape and near-IR measurements of emission-line ratios from the emitted optical. The emitted spectral range 912--1180 Åshows promise for abundance estimates in the redshift range for which it is accessible from the ground but not yet completely blanketed by the Lyman \alpha forest. This work was supported by NASA under FUSE grant NAG5-8959.