The LyB and OVI Forest in the Local Universe

Abstract

Intergalactic absorbers along lines of sight to distant quasars are a powerful diagnostic for the evolution and content of the IGM. In this study, we search known low-z Ly-alpha absorption systems for equivalent absorption in higher Lyman lines as well as the important metal ions OVI and CIII. OVI absorption is detected roughly half the time and shows a smaller range of column density than HI. This implies a multi-phase IGM with warm neutral and hot ionized components. We use our OVI detection statistics to determine that the fraction of intergalalctic mass at 10^5-10^6 K is at least 5% of the total baryonic mass in the local (z<0.15) universe.

3 pages, 2 figures. To be included in "Astrophysics in the Far Ultraviolet: 5 Years of FUSE"