Observations of the Interstellar Medium in the Magellanic Bridge

We present ultraviolet and optical spectra of DI 1388, a young star in theMagellanic Bridge, a region of gas between the Small and Large MagellanicClouds. The data have signal-to-noise ratios of 20 to 45 and a spectralresolution of 6.5 km/s. Interstellar absorption by the Magellanic Bridge atv_LSR = 200 km/s is visible in the lines of C I, C II,C II*, C IV, N I, O I, AlII, Si II, Si III, Si IV, S II, Ca II, Fe II, and Ni II. The relative gas-phaseabundances of C II, N I, O I, Al II, Si II, Fe II, and Ni II with respect to SII are similar to those found in Galactic halo clouds, despite a significantlylower metallicity in the Magellanic Bridge. The higher ionization species inthe cloud have a column density ratio N(C IV)/N(Si IV) about 1.9, similar tothat inferred for collisionally ionized Galactic cloud interfaces attemperatures 10^5 K.We identify sub-structure in the stronger interstellarlines, with a broad component (FWHM = 20 km/s) at 179 km/s and a sharpcomponent (FWHM = 11 km/s) at 198 km/s. The abundance analysis for these cloudsindicates that the feature at 198 km/s consists of a low electron density,mainly neutral gas that may be associated with an interface responsible for thehighly ionized gas. The 179 km/s cloud consists of warmer, lower density gasthat is partially ionized.Comment: Accepted for publication in ApJ (April 10, 2001). Minor corrections in Figures 1 and 3, and in reference