The fuse survey of high velocity OVI in the vicinity of the Milky Way

We describe an extensive FUSE survey of high velocity O VI absorption along similar to 100 complete sight lines through the Galactic halo. The high velocity O VI traces tidal interactions with the Magellanic Clouds, accretion of gas, outflowing material from the Galactic disk, warm/hot gas interactions in a highly extended Galactic corona, and intergalactic gas in the Local Group. Approximately 60% of the sky (and perhaps as much as 85%) is covered by high velocity hot H+ associated with the high velocity O IV. Some of the O VI may be produced at the boundaries between warm clouds and a hot, highly-extended Galactic corona or Local Group medium. A hot Galactic corona or Local Group medium and the prevalence of high velocity O IV are expected in various galaxy formation scenarios. Additional spectroscopic data in the coming years will help to determine the ionization properties of the high velocity clouds and discriminate between. the multiple types of high velocity O VI features found in this study.