THE GLOBAL CONTENT, DISTRIBUTION, AND KINEMATICS OF INTERSTELLAR O vi IN THE LARGE MAGELLANIC CLOUD

We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of interstellar O vi absorption toward 12 early-type stars in the LargeMagellanic Cloud (LMC). The observations have a velocity resolution of.20 km s1 (FWHM) and clearly show O vi 1031.926 A ̊ absorption at LMC velocities toward all 12 stars. From these observations we derive column densities of interstellar O vi in this nearby galaxy; the observed columns are in the range logNðO viÞ 13:9–14.6, with a mean of 14.37 and a standard deviation of 38% (þ0:140:21 dex). The observations probe several sight lines projected onto known superbubbles in the LMC, but these show relatively little (if any) enhancement in O vi column density compared to sight lines toward rela-tively quiescent regions of the LMC. The observed LMCO vi absorption is broad, with Gaussian dispersions 30–50 km s1. This implies temperatures T. ð2 5Þ 106, indicating that much of the broadening is non-thermal because O vi has a very low abundance at such high temperatures. The O vi absorption is typically displaced 30 km s1 from the corresponding low-ionization absorption associated with the bulk of the LMC gas. The general properties of the LMC O vi absorption are very similar to those of the Milky Way halo. The average column density of O vi and the dispersion of the individual measurements about the mean are identical to those measured for the halo of the Milky Way, even though the metallicity of the LMC is