  The number of detected baryons in the low-redshift Universe (z < 1) is far
small er than the corresponding number of baryons observed at higher redshift.
According to hydrodynamical simulations for the formation of structure in the
Universe, up to 2/3 of the 'missing baryons' may have escaped identification so
far, due to their high temperature and low density. One of the few ways to
detect this matter is to look for its UV absorption signature on the light from
background sources. Here we show that the amplitude of the average velocity
vector of 'high velocity' OVI absorbers detected in a UV survey of AGN
decreases significantly in moving from the Local Standard of Rest, to the
Galactic Standard of Rest and Local Group frames. At least 82 % of these
absorbers are not associated with any 'high velocity' HI complex (HV-HI) in our
Galaxy, and so are strongly implicated as being due to primordial Warm-Hot
Intergalactic Medium (WHIM) pervading an extended Galactic Corona or our Local
Group. We estimate that the total baryonic mass contained in this medium is as
large as ~ 1e12 solar masses, similar to the combined mass of the two most
massive virialized constituents of the Local Group (the Andromeda and the Milky
Way galaxies), and of the order of the mass required to dynamically stabilize
the Local Group.
